Mikoto Itoshiki is the older brother of Nozomu Itoshiki. Mikoto is a doctor at the private Itoshiki Clinic. He is the third child of the Itoshiki family and has a great resemblance to Nozomu.
His name in kanji, when written sideways, gives out the name Zetsumei, which means "Death", ironical for someone who has a profession of giving life to people. This may be the reason his clinic is visited by so few people. Nevertheless, he still pursues on with his career.