Low voice, very deep with a "I hate my life" kind of feeling to it. Makes the "Tch" noise a lot when he's angry. He only laughs when it's Sadistic.

chimatsu is the "loner" of the Matsuno brothers. He has an affinity to cats and chooses to spend time with them instead of people. Because of this, his brothers see him as incapable of friendship, despite the truth that Ichimatsu is just not self-confident to befriend others. However, it very so happens that Ichimatsu actually has a difficult time expressing himself.

He is still commonly seen with Jyushimatsu, sharing a close relationship with him. This is exemplified in episodes such as 9B: Jyushimatsu Falls in Love, where Ichimatsu voluntarily offers to serve as added weight on Jyushimatsu's baseball bat, even when clearly shown to dislike it (though, the reasons behind this are questionable; some may argue that this contributes to part of Ichimatsu's "masochistic" nature, which was offhandedly mentioned to be part of his official character description in the 3rd installment of Osomatsu Radio).

Ichimatsu seems to hate his brother Karamatsu for an unknown reason, going so far as to dance with glee when Karamatsu was kidnapped in Episode 5A: The Karamatsu Incident.