Daisuke Kusuriya

The main protagonist, it is believed that he is the strongest host in SEPB. His alias is "Cuckoo" (かっこう, Kakkō, lit. Cleridae). Years ago, he shot Shiika's mushi, and promised her to make her dream come true. However, he does not seem to realize that Shiika was the girl he made the promise to. He has a sister named Chiharu, whose whereabouts are currently unknown. His mushi power manifests in powering a gun he carries. It is hinted that the more powerful he makes the bullet, the more his dreams or energy is drained. Wikipedia