is the main protagonist of the story, a perverted second-year student at Momozomo Academy, who uses his perverted spirit-energy to give Lisara energy. Also, he learns from Lisara that he will die in three months and in return for his help, she will try to change his fate. Lisara uses the Broken Sword, Gram, which used to belong to the God of War, to form a contract with Ryosuke. However, it was revealed later that Ryosuke has the other half of Gram (which was thought to be lost), thus gaining full power of the sword. It is shown that he loves Lisara, and can only fully charge his perverted spirit energy if it is her body alone or with his "Invisible Dictionary". He lives all by himself (until Lisara moved in) while at the meantime his mother works overseas; his father's location is unknown.