|Eyes||Blue and Yellow|
Yoru is a tall man with spiky dark blue hair. His left eye is blue while his right eye is a glowing amber or yellow colour. It is suggested that Yoru might have Heterochromia Iridum. Yoru can be distinguished from Sora by his slightly darker hair, increased height, deeper voice and a glowing amber left eye. Yoru is seen wearing a black singlet and long pants but is sometimes seen in costumes, as seen in Episode 2 when he suddenly appeared when Sora was cosplaying as a swordsman. He is also usually seen with a long white piece of cloth tied to his right arm. In one of the drama CDs it is said that he tried to kill himself because he left Ran in the lab, and wears the white cloth as a memento.
Unlike Sora, Yoru is both shrewd and flirtatious. He is seen being more physically and mentally mature than Sora, him being taller than Sora and the way he talks and his deeper voice. He is usually always shown with a smirk on his face. Yoru loves Ran and is considered the seme of the couple. Yoru isn't above flirting with anyone unlike Ran. He likes to do erotic stuff with Ran in bed, which embarrass Sunao Fujimori in the aftermath. Despite his shrewd personality, Yoru does have kindness. He would always help out Sora when the latter is in need of help. He is also shown to be humorous when he likes to joke around with Sora by placing images of Sora's friends in erotic positions, including Sunao and Ran, Hiromu Sakura, Kai Nanami, and oddly enough, Yoru himself.
- Yoru's name means "night" in japanese, as shown in episode one when Ran calls Sora Yoru and Sora thinks Ran is referring to the night outside his window.