Mariko is the antagonist of Dear Mariko. A game by SoyaSushi Productions about a girl recalling fond memories from the past after she returns home to find her boyfriend missing.
Her appearance is slightly ambiguous. She is a teenager with long brown hair and a fair complexion. By her disheveled appearance, it is made apparent that she hasn't been taken care of herself. She wears a pale blue school uniform.
Mariko was said to be an affectionate and sweet girl who admired Darien and fell for him quickly. She blamed herself for the strain in their relationship, and hated herself for being unable to tell what was wrong. From his (unintentional) neglect over the course of time, she was driven into a stress-induced breakdown.
Not much is explored for Mariko, other than knowing she hooked up with Darien two years prior to the game.
She wielded a knife.
Shinku - If Shinku is unable to hide from her and find protection before she gets into the house, Mariko will find her and kill her.
Darien - Before Shinku got involved they had a great relationship and loved each other. She was aware of him distancing himself but only got concerned over it when it was growing worse. From the stress of Shinku and feelings of abandonment from him, she was driven into Yandere mode. It was implied that when she shows up at the end of the game, she had the intention of killing or harming Darien.
Shinku - It can be assumed that Mariko hated Shinku as much as she hates her. By the time she found her, she eagerly killed her while calling her out for what pain she caused.
In the True ending of the game, she is killed by by Shinku whenever she finds her hiding in the home. She pleads and cries out for Darien to save her, further angering Shinku and causing her to stab her repeatedly.
- She is only revealed to be Mariko during the True Ending of the game, when Shinku will say "Goodnight, Mariko." Before finishing her off. On the other route, she is the assumed-stalker.