Tsurumi is Komaki's classmate. He's the main male character of the story, and he also has a particoular ability. Hana, in fact, confirm the suspect that Tsurumi also has an alien "sleeping" inside his head, and due to this, he gained a very high developed hearing. Since his alien is in this sleeping-status, he's not able to talk to him, like instead Komaki is able to do with Hana. Due to his ability, Tsurumi is able to often save Komaki or Rika. Tsurumi, like Komaki, is able to understand when people lie. Strangely, Tsurumi (together Numa-sensei) is the only one which Komaki isnt able to sniff the smell. She just felt it once. Later, it's explained that Komaki isnt able to feel his smell anymore, since she rejected it, at the very start, when she still wasn't used to her new sense of smell, together all the rest of bad smells. At the start, Tsurumi seems to be the only one that, after the bad accident happened to Rika, Kurokawa doesnt "phisically reject". Also, due to this fact, he little by little make her recovering from the bad experience. She soon starts this new habit, which is, holding his hand everyday during the travel from home to school. He is the one who named Rika "Queen of sex". As personality, Tsurumi is a quiet guy, he looks to be cold towards the people who loves him, but instead, is the classic gold-hearted boy of the circumstance. Tsurumi has a grandmother which is really attached to, and she helped him to live with his ability of him. When she dies, he only shows his tears to Komaki.

He always loved Komaki, always protected her and pandered what she wants saying that he only wanted her to be happy, as it's hinted in the whole story he loved her from the start, since she was the first person that didn't feel disgust for him when discovered his ability and rather kept her usual behaviour. At the end the two end up together.

During the story, Tsurumi's first name was never mentioned, his grandma was used to call him "Gin-chan".