Yuuichirou Kumada
Yuuichirou is the struggling musician who showed up on Rei's Temple steps one day and immediately fell in love with Rei. He started to train under Grandpa Hino too, so he could get over stage fright. Rei firmly says he can't sing, and will chase after him if he does.
One time Yuuichirou saw Rei and Haruka together and thought she was Haruka's boyfriend, so he decided to leave the temple. Rei thought he was just being stupid so he didn't tell him what was really going on. As he headed out to the train station (his voice actor sang a really sad song which sounded great) Usagi convinced Rei to go after Yuuichirou, and stop him from leaving.
Another time when Mamoru was staying the night at the temple. Yuuichirou finds out that Mamoru used to date Rei, so he sneaks behind the tub where Mamou is at, and heats up the tub (because the stove gives it hot water), and makes the water boil which boils poor Mamoru. Rei accidently walks in and runs out screaming.
It was shown that Yuuichirou wasn't living at Rei's temple but living in his own condo. His parents are very rich which suprised Rei. He was a great skier like Rei and they often competed.
Yuuichirou will do anything for Rei, but Rei doesn't show that she actually is interested. She tries to play hard to get but Yuuichirou doesn't understand, and gets the wrong impression. She really does have a crush on him but won't admit it.