Mitsuo Yanagisawa (柳澤 光央 Yanagisawa Mitsuo) is a freshman studying law in a private university in Tokyo.
Mitsuo is a handsome young man with dark blue hair and blue eyes. However, he dyed his hair blond after he was rejected by Chinami Oka.
Mitsuo is a good man and has a mature nature. He is easily distracted, as seen when he found people who followed him. At first, he finds the personality of Koko Kaga extremely annoying. However, he mentions "they are still childhood friends" and even worries about her sometimes, as displayed when he sent texts showing his concern when Koko was "kidnapped" by the religious cult.
After bumping into him at a convenience store, Mitsuo and Banri Tada soon become friends. While walking to college with Banri, Koko stepped out of a taxi and slapped Mitsuo on the face with a rose bouquet, congratulating him for being accepted into college. Arriving at college Koko Kaga introduces herself as a new student at the grounds, as well as declaring herself Mitsuo's fiancée. In class, Mitsuo goes on to explain their history to Banri, even declaring that he dislikes Koko's attitude, not knowing that she is sitting right behind them, causing him to run at the sound of the bell
Mitsuo met Chinami Oka in the Film Club, and after getting to know her more, he was immediately romantically interested in her. Though, Koko's persistent attitude prevented him from approaching her at first - until Mitsuo invited Koko and Banri to a cafe where he rejected Koko's feelings for him outright, stating that he wanted to get romantically involved with Chinami. This caused Koko to have a grudge against Mitsuo (which slowly disappeared after she started dating Banri), and Banri to sympathize with Koko. When Koko, Banri and Mitsuo were invited to a Film Club party that Chinami was organizing, Koko provoked Mitsuo by saying he could never confess his feelings to her, no matter what he says otherwise. Of course, Mitsuo insisted that he could and confessed his feelings to Chinami right in front of Koko, saying that he loved her and wanted to go out with her. However, Chinami responded with a smile, saying: "Don't be stupid." Having to been rejected on the spot, everyone at the Film Club party secretly laughed at the heartbroken Mitsuo. For a while, he couldn't even face Chinami without running away.
After getting realizing that he needs Koko in his life, he apologizes and ask her if they can start over.
- Mitsuo later becomes romantically interested in Linda (it is shown that Linda likes him back since she was seen smiling and blushing at him at the end of Episode 24).