Sumi's alter ego when she transforms. Tadano Jun actually means "only Jun, nothing else", but Kyouoko misinterpreted and assumed his surname is Tadano. Jun draws a lot of attention and holds a great deal of charisma. As Jun, she can talk to Mitsuru easily as a man. Jun gives good advice to Mitsuru as he wants to be like Jun. He rejects the advances of Kyouoko, and is constantly being chased by other girls. Even though Sumi is in the form of a man as Jun, she likes Mitsuru just the same.