Ken is a 2nd Year student, and holds the Student Council "Blue Chip" Seat and Vice President. He entered the student council as the top-scoring student in his year; the highest scoring student automatically receives a place on the student council. He had to work hard to improve his score, being in the lowest score bracket when he enrolled. He is referred to as "Kii-kun" by Chizuru, from his given name Ken which also can be read as Kagi (a key). Loves playing eroge and galge, and plans on making the rest of the student council members his harem. On the surface, he seems to be lazy and carefree, but he is actually very hardworking and always stays behind after dismissal to finish all the student council work so that the student council can have fun as always. Ken also has a serious side to him, and he truly cares for those around him; According to Kurimu, they are yet to find someone Ken dislikes. Ken reveals to Lilicia that the student council itself is his "dream", where his goals and happiness co-exist.
But he has an obsession creating a harem making everyone happy but is slowly coming to realize it isn`t possible which she aware of and is wating for him to completely realize it.
Eventhough they already broke up before Ken transfered schools, it doesn`t seem like they actually broke up when they are together. He still acknowledges her as the first girl part of his harem and she even introduced herself as his wife and addressed him as her husband.