Yamikumo Kerin (ヤミクモケリン) is a male Japanese Virtual Youtuber.
Kerin is a 19-year-old dark elf who currently resides in an elven village in virtual Gunma prefecture. Aside from being a YouTuber, he also works at a factory in a nearby town as a janitor.
His personal hobby is making missiles as well as other weapons of mass destruction and he funds his projects by stealing from the village's revenue. He often conducts missile tests and missile raids on targeted locations and individuals, most of which tend to end up failing due to some inevitable malfunctions and other miscellaneous contingencies, resulting in him blowing up himself and/or attacking the wrong targets.
Despite his extreme behaviors in his videos, during livestreams he seems to be quite restrained, giving people the impression of a very polite and humble young adult.
- Kerin's real name is actually "Karin", and the people from his village refers to him as such  . "Karin" is Japanese for "the flower of Pseudocydonia sinensis ".
- Having been a member of the Virtual Youtuber group "BANs", Kerin left the group on July 29th, 2018 along with two other former members Space Monster Anchin (宇宙怪獣アンチン) and Axes / VRISSA (ドーセット・アカホシ), becoming fully independent ever since.
- Kerin is known for using the North Korean propaganda song/meme "공격전이다"/"Gonggyeokjeonida" (lit."Offensive campaign"), otherwise known as "Kongyo" among Japanese netizens, in his videos where he conducts missile launches, earning him the title "コンギョ系Vtuber" ("the Kongyo Vtuber").
- His most iconic line is "ぶちとばしていくぜ！！！" (Buchitobashite ikuze), which loosely translates into "Let's blast the f**ck off !!!".
- Kerin has the ability to shoot missiles from his crotch.
- Kerin also claims to know dark magic, but no one has ever seen him successfully perform one. He later on elaborated that his dark magic skill has the ability to blind other people.
- His missiles are not powered by explosives, but by "magical substances".
- He didn't go to college because he "doesn't like using his brain."
- His favorite snack is Snickers and his favorite drink is Red Bull,
and Lion Blue.
- Kerin is also known for being an avid fan of Elu the elf, a Virtual Liver from Nijisanji. In fact, his maniacal fixation on Elu gave birth to one of his most iconic quotes "Elu-san suko da" (I love Elu-san).
- Surprisingly, Kerin is friends with Nijisanji's COO, Iwanaga Taiki. It began when Kerin found out that Iwanaga retweeted his video on twitter one day. Kerin started following Iwanaga on twitter and proceeded to use him as a meme in his later videos. Despite constantly being made fun of in Kerin's videos, Iwanaga is really chill with Kerin and followed him back, due to himself also being quite the meme-ful person. Kerin and Iwanaga also played PUBG together  .
- Canonically speaking, Kerin holds a deep grudge against Tsukino Mito and Higuchi Kaede for burning down Elu's forest. In his videos, he attempted to rain napalm bombs on Kaede but failed due to malfunctions and blew himself up. He also attempted to attack Mito in the act with a fighter aircraft, but was stopped by a giant figure of Iwanaga (?). He refers to Mito as "Sabukaru Kuso Onna" ("Shitty sub-culture bitch").
- There is an ongoing rivalry between Kerin and Domyoji Haruto from Game Club Project simply because Elu said that recently "Haruto caught her attention" in one of her livestreams. Kerin then declared rivalry on him by defacing his portrait with a crotch missile and replaced it with his face.
- Kerin was one of the participants in the 2018 Kizuna Ai Cup Mario Kart Tournament. He made into the semi-finals but was disqualified, ranking third place in Group A.
- He successfully "bombed" Kizuna Ai in retaliation in a video  because she sent him a "death threat" for snatching away a power-up in front of her during the qualifying round of the 2018 Kizuna Ai Cup, giving him the title "The first ever man to bomb Kizuna Ai". The title was later on recognized by Kizuna Ai herself. However, despite the bravado he put up against Kizuna Ai beforehand, he was quite polite and respectful towards Ai when he was being interviewed by her after he was disqualified in the semi-finals.
- Kerin's videos tend to incorporate a lot of Niconico memes and Japanese internet memes in general. More importantly, his video format is heavily influenced by what is known as "BB劇場" (BB Gekijou, "BB Cinema"). It is a shitpost-ish video genre that is very popular on Niconico, which consists of putting together a bunch of green/blue screen assets that are either still images or GIFs.
- On 21 October 2018, he became a member of the Virtual Youtuber support group Upd8  . Since Upd8 isn't a Vtuber agency, he is still technically independent.
- On 13 February 2019, his Master, the Dark Elf Angela Fray made her debut .