Sananana
Sananana is a famous voice actor who starred in Cookie☆☆/S3 (24/12/2013) as Reimu Hakurei and in Nabe☆ (7/1/2014) as Koishi Komeiji, as well as having parts in 外部交流☆ (as a character named Dolce) and in ガン掘り！ (8/24/2014～9/11/2015). The TDN-notation name is confusingly similar to Shinonome (SNNN vs. SNNM).
Her acting skills are comparatively high, likened to that of a radio operator, and she has many ranges for her voice, from a small little child to a mature big sister. Her line delivery is especially smooth and even when she's not acting, she can speak light-heartedly and fluently, or courteously and respectfully.
She has been involved in a wide variety of activities at the Koe Club (a community based around voice acting) but her relations to idols and magical girls are the most prominent.
She had not much involvement in Cookie☆☆, but she was angry over MADs being made from 外部交流☆, so she deleted all her accounts as if she was taking responsibility. She essentially retired and cancelled most Internet activities, but her popularity still persists. Her characterization and design is absurd and eclectic, with high associations to concepts like magical girls, dolphins, concealment of her age, pubic hair, and many other such netas. She remains as a decently famous RIM-role to this day.
History
Voice Drama Role
Cookie☆☆/S3
Sananana appears as Hakurei Reimu in the final voice drama in the Taisa trilogy. Here, she hangs out with Yukari, Marisa and Alice, at the Hakurei Shrine during Christmas, telling Yukari off for flirting with her. The four talk for a bit before the sudden appearance of Youmu and Yuyuko through a hole, who tell the four about a thief stealing Christmas presents, wanting to enlist their help to capture the thief. Despite Reimu's lack of enthusiasm, she nonetheless accompanies the search party for the Christmas present thief, encountering various Gensokyo residents along the way. At the end it was revealed that Marisa was the thief, and they all go back to the Hakurei Shrine to spend their Christmas.
Nabe☆
Sananana plays the role of Komeiji Koishi in this voice drama. In the beginning, she was looking for something to keep warm during the winter season. So, she decides to hold a hot-pot party, invites the entire cast to the Palace of the Earth Spirits, and sets the plot in motion. The ingredient she put into the hotpot was a single manjuu bun that Satori did not like eating, but was forced to eat anyways. On Koishi's turn to eat, she happens upon something "long and hard" and inedible, forcing her to turn the lights back on - turns out she nearly ate Utsuho's control rod, causing her to chastise Utsuho. At the end of the party Koishi and Satori rest at a hot spring and discuss the day's events, with Koishi planning to hold another party sometime.
General History
Not much is known about Sananana owing to lack of information, but it is known that she has a hobby of scuba-diving and owns a guitar. She was popular from an early stage and was being investigated by the main Cookie☆ threads. However, since Sananana was not active in anything other than the Koe Club, people didn't have much fun. No Twitter account or other activities outside of the Koe Club have been discovered. In general, not much info about voice actresses in Cookie☆☆ have been exposed. However, a different account named "羽丘" has been discovered to be Sananana, under which she participated in the voice drama ガン掘り！(August 24, 2014-November 9, 2015) playing the role of Atago from Kantai Collection, which was christened "HNOK". The name "HNOK-aneki" is a combination of this name and the Inmu character Tanioka.
An account with Sananana's name was found on Pixiv, so it was theorized that she may be 27 years old. It was found out, however, that the Pixiv account was owned by a different person and had a different date of birth than Sananana's confirmed account on the Koe Club. Even with this revelation, the age became a hot topic and Sananana was portrayed as a 27-year-old big sister who wouldn't admit their age. Due to people thinking the age was Sananana's actual age even though it stemmed from misinterpretations and gossip, the SNNN-system was established to refute it and release the real information about her age.
Taking advantage of the lack of information, it was popular to create an image of Sananana based on what was known about her, also because of the existence of the SNNN-system. In particular, her hobby of scuba diving was construed into a lust for dolphins, which was popularized for her character and spawned a notorious copypasta.
Even today it isn't talked about much, the idea has been passed on to the Iruka-Thread (Dolphin-Thread).
Dolphin-Thread
The main animal associated with Sananana, and the name for the de-facto Sananana worship thread. She gets treated like the personified character created by the Hon-thread, and perverted characteristics get added on a daily basis. In addition to being a pervert, she's also treated as dirty (in the sexual sense). Here, we don't see the pairing with Rei, like in fanart, but instead the stories are focused on "shota"-type works. Also, she often works with Hisui as a partner and rival, and a trio with Amelia (also from 外部交流☆) being pushed around and bullied by the two is popular.
On another note, dolphins in real life have a cutesy facade and reputation, but are notoriously infanticidal and serial rapists. There is a possibility that the fellows in the Dolphin-Thread may have taken inspiration from the behavior of real dolphins, though it's probably just accidental.
Voice Drama Activities
She gets treated as an annoying adult who participates in children's voice games unsuitable for her age.
After her appearances in Cookie☆☆ S3 and Nabe☆, it appeared as though she disappeared from Internet activities. However in 2014, she changed her name and appeared in a non-Touhou voice drama, 外部交流☆. Despite the name-change, the voice drama was discovered anyway, and was established as a live-video recording. In real life, she was also a popular voice actor with well-known character songs , but both the organizer of 外部交流☆ and Sananana herself were angered by the MADs being made off their work. After the "diplomatic issue" where Sananana deleted her account in a way that seemed to take responsibility, people refrained to talk about it. The Inmu community and other Cookie☆ branches did not talk about this so much, so the topic of Cookie☆ Livestreaming became the isolated genre it is today.
After this, she was somewhat active in the Koe Club for a while, and starred in another voice drama playing the role of Kancolle's Atago in ガン掘り！, before shutting her account down and fully disappearing from the Internet.
In Derived Works
Character
At first, Sananana had a weak association with Reimu, and didn't attract much attention from the fanbase. She didn't have the chance to shine in the spotlight for quite some time, but with the advent of the RIM-Family's popularity on Nico Seiga, Sananana in turn enjoyed a boost in popularity, mostly in Nico Seiga illustrations which later influenced the Nico Douga video community and had many appearances in BB theaters and MADs, and is most often portrayed as the Reimu from Cookie☆☆ S3. Thanks to the Cookie☆ content creator UMO, the netas derived from the Hon-thread like age, being an office lady, dolphins, pubic hair, idols, magical girl and the like have been popularised by his works which at that time were popular and influential. This fundament is still used and develops on its own. Her Koishi role from Nabe☆ also sees occasional appearances. Her role as Dolce from 外部交流☆ and Atago from ガン掘り！ never see any use, though her appearance in 外部交流☆ has led to her being occasionally grouped with Amelia and Hisui.
As a character, her personality and attributes are strongly influenced by fan art on Seiga, and is often portrayed as a past-her-prime big sister who yearns to be an idol at her age, as well as the eldest daughter of the RIM family. Depictions of her as an overworked, stressed, alcoholic office lady, who is unable to see her family due to tons of work, and the perverted, dirty, and desperately horny representation of Sananana thought up by the Dolphin-Thread and Hon-Thread, are also prevalent, and Sananana nowadays sports a combination of these personalities when shown in BB theaters. Her abilities within illustrations and BB theaters include the capability to actually transform into a magical girl (called Magical Girl Idol Momoka) complete with special powers and a magic wand tipped with a ying-yang orb, the usage of her affinity to dolphins by riding them as a mount even outside water, and prehensile, flexible pubic hair.
A common joke is to append as many "N"'s or "Na"'s as you'd like to the end of Sananana's name or TDN-notation moniker, forming a ridiculously long name (something like Sananananananananananananananananananananana or SNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN姉貴)
Relationships
The most popular coupling for Sananana is her coupling with Rei, called RISN (shorthand for Reisana), coming about due to perceived age differences and being co-stars in Cookie☆☆ S3. Due to the common portrayal of Rei as a young effeminate boy, or less commonly as an actual young girl, and the portrayal of Sananana as a desperate past-her-prime big sister, this pairing is almost always depicted dirtily, with many illustrations and videos depicting Sananana forcibly fornicating with an unwilling Rei. The lewd depictions of the pairing is said to be the result of the Dolphin-Thread's influence seeping into general Cookie☆ art. Sometimes though, the two will have a genuinely amiable and platonic relationship, as general friends or as co-workers, or the two have a actual big sister-little sibling relationship without any lewd connotations, or Rei gets their revenge and turns the tables on Sananana somehow.
Other than Rei, she sometimes teams up with fellow Cookie☆☆ S3 voice actress Hisui, and as a duo they bully, cajole, and even force themselves onto Sananana's fellow 外部交流☆ co-star Amelia, who is another young girl. This depiction is rather uncommon, especially after Hisui's big break in popularity, change in popularity, and the formation of Hisui's own group, but still sees the occasional appearance.
As the eldest sister of the RIM-Family, she's established as the second most serious and mature one to the eclectic and goofball nature of her sisters (and brother). Usually Kanna is the most mature one but even she joins in on the antics once in a while. Sananana is portrayed as spending extensive amounts of time away from her family due to being swamped in huge amounts of work, but she still loves and cares about them, and joins up with them in events or family outings whenever she can. Also, she is sometimes treated as a character who is liked by Suzuki, contrary to Kanna's mutual hostility with him.
Within the office setting, it was established that Sananana has a friendly co-worker relationship with Ryuuga, and will often go out drinking with her after work and give her advice. Other characters may have work relationships with Sananana depending on the author, such as Shiromiya and Rei.
Design
Sananana always takes on the design seen on Cookie☆☆ S3's first non-MMD release - in an art style known as the "New Christmas Style" after the name of the voice drama. She is also seen in a variety of outfits, her magical girl outfit sporting a frilly pink dress and a special magical rod and her business suit office lady outfit being among the most popular. Sometimes the MMD models might be used for Sananana - particularly in MMD-styled videos.
Other Netas
Age
Either (23) or (27). It started as (27) and then changed to (23) but then the ages became more and more inconsistent. As stated before, the origins of the age being (27) was due to a person with a similar name on Pixiv with a given age of 27, but this was denied and the Pixiv account owner out to be a different person. This exchange about her age became a main topic and the concept of Sananana lying about her became a common characteristic for her portrayal in Cookie☆. This was reinforced by the fact that many of her voice lines were age-related, such as "I'm in my twenties."
Pubic Hair
The idea of "Adults (of the aforementioned age) = thick pubic hair" and stories about said hair being seen became a hot topic. This can be taken further by saying it's bristly or it's smelly. In Cookie☆ derived works, Sananana's pubic hair has somehow become a superpower of its own, being controllable, flexible, and able to become powerful tendrils to capture or entangle people.
Magical Girl Idol Momoka
Sananana's usual name for her magical girl persona. Originates from the voice audition posted on the Koe Club account, in a speech where she says she wishes to be a magical girl and narrates the introduction for a fictional magical girl anime wherein she refers to herself as Magical Girl Idol Momoka.
Kyle the Dolphin
Purported to be the name of the specific dolphin that Sananana takes care of. Kyle was originated and was first named in a particularly infamous and incredibly long copypasta about Sananana having sexual relations with dolphins in an aquarium, particularly one such dolphin named Kyle. A Japanese reading of the copypasta in question can be watched here. In his few appearances, Kyle is represented as the Neo-Spacian Aqua Dolphin from Yu-Gi-Oh!. Sananana's talking skills and hobby of scuba diving led people to expect her to be a presenter at an aquarium, and dolphins are a common sight at aquariums, causing the development to the idea that Sananana lusts after the dolphins under her care.
Sasanana
Misspelling of Sananana in the Cookie☆☆S3 voice drama video.
Crooked Sananana
A bizarre alternative version of Sananana with a unusually crooked mouth shape that "speaks" a weird language in the form of reversed voice clips. Crooked Sananana is treated as a separate character, and she is only ever seen in relation to Hisaka. Crooked Sananana first appears in "HSK Sisters BB" (January 30, 2018), whose surreal subject material led to Hisaka's popularity, and the association of Crooked Sananana with her. Hisaka and Crooked Sananana are often depicted in collage images and as characters with huge crooked faces, arms and legs.
Jacking off onto the floor
A mishearing of a line of the Cookie☆☆S3 voice drama.
"Maybe you should fix my floor" -> "Maybe you should jack off on my floor"
The holy land of Sananana fans
This is a tag that is often attached to Sananana's main otoMADs.
The tag "holy land of [...] fans" has been widely used not only for Cookie☆, but also for videos that fully express the loveliness of the character. However, even though the videos tagged with "holy land of the Sananana fans" carry the tradition of a Cookie☆ otoMAD being a bait-and-switch (Ittenkousei) video that transforms into an Inmu otoMAD, the specific focus of the bait-and-switch for Sananana otoMADs : an Inmu character named Gabber Hole Daddy infamous for his incredibly shrill and loud voice, ear-rape videos, and dirty dialogue, still leaves a heavy impact on even viewers that predict the bait-and-switch. This particular bait-and-switch is sometimes called a "beauty contest".
This format has been a classic in Taramuki's videos, starting with "Sananaito no Gyakkou" (January 5, 2017), and he has posted many of them by himself. However, other contributors have taken advantage of this situation and it is finally becoming a standard otoMAD format for Sananana-centric videos. For example, "Sananana Angel" (March 7, 2019) masquerades as a cutesy and trendy Sananana otoMAD then goes full-circle and blasts the listener's ears with high-volume distorted Gabbar Hole Daddy voice clips (and other Gabber Hole Daddy-related characters),