Hakuoki ~Demon of the Fleeting Blossom~

After his brutal defeat, Heisuke drinks Ochimizu and becomes a Rasetsu. An attempted assassination leaves Commander Kondou in critical condition. In order to avenge Kondo, Souji drinks the Ochimizu that Kaoru gave him, also becoming a Rasetsu. Kaoru appears, and reveals that the Ochimizu will not heal his tuberculosis. He also reveals the reason he hates Chizuru. In an ensuing battle, Souji manages to kill Kondo's attackers, but is also heavily wounded by gunfire. With both Souji and Kondo close to death, Hijikata sends them to Osaka Castle to be treated by Doctor Matsumoto. (Source: Wikipedia)