Ayamada Hikari (Yandere Kohai)

Biography
Ayamada Hikari is a female teenager attending high school with Suzume Okayaki and Senpai. Hikari has always suffered with mental illness but Okayaki's bullying have only made them worst. In school she was an outcast and took the burden quietly. Home wasn't much better. Hikari's parents were very controlling and fights began to become more and more frequent. One day the voices in her head got louder and louder until... Hikari snaps.

Hikari leaves alone now. Her parents moved away. School life continues to be full of harassment, neglect, and wary glances. All of sudden, Senpai transfers into the school. Unaware of the stigma, Senpai treated Hikari with open kindness. Eventually Hikari's emotions grew and became warped. Obsessed, she began to stalk Senpai after every school day. Sometimes she would even use a ladder to gaze at his sleeping face. One day Hikari sees Okayaki holding hands with Senpai after school. The voices return, louder than ever until... Hikari breaks.

Personality
On the outside, Hikari may seem shy and reserved but underneath is a torrent of repressed rage. She frequently deludes herself in fantasies to calm her violent voices.

003 Diary Of A Yandere Prologue
[Monday, June 5th 2017 to Monday, July 10th 2017]

Sometime before Hikari has already killed her parents and have placed them in the basement. She writes her first article after meeting the new boy, Senpai, whom she falls in love with on sight [Monday, June 5th]. She explains the calming effect he gives off to her just by being near [Wednesday, June 14th]. Unable to bear the distance they share in school she begins to stalk Senpai home everyday after school [Monday, June 19th].

However one day she spots her bully, Tsundere Suzume Okayaki, talking to her Senpai [Thursday, June 29th]. The same Suzume Okayaki that's been harassing her all throughout the school year. Freaking out she decides it must be something about homework and reconfirms no other girl can have him. After the incident everything seems to have return to normal including her stalking cycle. Finally one day she convinces herself to leave Senpai a confession letter [Friday, July 7th]. However she gets nervous and decides to just continue stalking Senpai. But this time she sees Okayaki holding hands with her Senpai. She goes berserk, knocking out Senpai and stabbing Okayaki to death.

001 A Yandere Kohai Kidnapping
[Saturday July, 8th 2017]

In a panic she brings both of their bodies back to her place. She then confesses to Senpai only for him to lie and try to escape. Pent up with his bad behavior Hikari decides to give Senpai some "tough love". She then leaves him alone to deal with the Tsundere's body.

006 Breakfast In Bed A Yandere Kohai Kidnapping Part Two
[Late Morning, Saturday, July 22nd 2017]

Just before going to sleep together her Senpai tried to escape. So she took out a hammer and "fixed" his legs so he couldn't get lost ever again. She then attempts to surprise Senpai by cooking some Brunch but Senpai refuses to eat. That's when Hikari decides that a "little push" is needed to help Senpai eat. He even manages to compliment on how tasty the food is.

013 Anniversary Dinner A Yandere Kohai Kidnapping Part Three
[Early September 2017]

On the two-month anniversary of their relationship, the couple begins their dinner before someone comes knocking on the door. Its another student sent by the school to go check up on her. After they insist on making such a fuss Hikari takes it as an opportunity to test Senpai's love. After kidnapping the intruder she gives Senpai a knife to prove his sincerity. If he's good then he must be really be in love with Hikari; but if he's bad then she'll do it and give him some "punishment". Hikari proud of Senpai's decision decides to leave on a vacation for a while.

023 The Necromancer
[All-Hallows-Eve, October 31st 2017]

Suzume Okayaki swears to get revenge on Hikari for murdering her.

025 END A Yandere Kohai Kidnapping Part Four
[Four? Five? Six Months after July; Presumably sometime in November 2017]

After more than a year of helping Senpai adjust to being her boyfriend, she decides its time to tell her parents. Bringing Senpai to her basement she invites him to the table. Instead Senpai breaks down her delusion and brings Hikari back into reality. Contemplating double suicide she easy knocks out him out as she slowly comes to her senses. The next day she tells him all about her life and how she has no regrets except her blindness to think that Senpai would one day fall in love with her. Tired of her helpless situation she even contemplates letting Senpai kill her as a good way to end. Knowing she's being selfish again she decides to take Senpai with her to what ever lies beyond. Thanking Senpai for waking her up she commits to her happy ending.

Senpai
Her attraction to Senpai began when he showed her the slightest bit of kindness. A rarity as the rest of the school already knew Hikari as the "crazy" one and would leave her open to harassment and depression. Coupled with the voices she hears in her head and the result's a tragedy.

Despite all the resistance Senpai gives, she's unable to give up on her deluded hope. Eventually she even copes Senpai into murdering a fellow schoolmate to solidify their "love". But after realizing her parents are dead she decides to commit a "lovers?" suicide despite knowing its only for her happiness.

Tsundere
At the beginning of the year, Tsundere Suzume Okayaki, has been bullying her on at least five separate occasions. Her behavior causes Hikari to carry a grudge as the ringleader of the bullying as noted in her diary. Notable mentions include stealing her gym uniform in the locker room and leaving nasty notes in her locker. Hikari is only saved from further harassment by being a grade lower than her and thus in a different homeroom.

After spotting Okayaki holding hands with her Senpai, she goes absolutely berserk. Berserk enough to even hurt Senpai to avoid him from interfering as she releases years of abuse into cathartic knife swings. She even imagines it would be fun to burn her body like a witch's.

Hikari's Parents
Not much can be said of them except by what Hikari tells about them. Apparently they were quite protective about her. Her dad was especially concern with preventing Hikari from dating without their permission. After an argument, the voices in her head caused her to lash out and murder them.

Though Hikari shows genuine sadness about her dead parents it can be inferred she was quite neglected. They never even knew that their daughter was dealing with severe symptoms of schizophrenia. They also either never knew or never cared to act on all the bullying she was dealing with until it literally came back to stab them.

Trivia
Its most likely Hikari was based on the Queen of Yanderes, Gasai Yuno. Some similarities include killing off her parents, strapping her lover to a chair to keep him safe, and even breaking out of her delusions at the end.

She also shares similarities with Yandere-chan from Yandere Simulator fame. Beyond just their similar appearances both receive an indescribable feeling whenever they're near their respective Senpai.