Momioka Risa

Risa Momioka is Haruna's and Mio's best friend and Rito's and Lala's classmate. Her favorite thing to do is to grope the girls breasts and whisper naughty things to their ears.

Appearance
Risa is an attractive girl with dirty blond hair and dark brown eyes. She has a curvaceous figure (though not at the level of Lala or Yui) and seems to have some trouble keeping some men at bay. Of all her class mates she is probably the most willing to use her figure to attract attention, save for comedic scenes.

Rito Yuuki
It has been shown that Risa might have feelings (or at least lusts) for Rito but it hasn't been detailed if she was serious or joking. This is shown in the manga chapter: 147 and on episode 10 of Motto To Love Ru Trouble episodes.

Rito wishes that the naive Lala would stop taking advice from Risa and Mio. And Risa doesn't take Rito's rejection of sex and temptation seriously, and likes to tease his shyness around girls and occasionally gropes other girls in front of him. While various other girls consider Rito to be a pervert, Risa knows that he is an innocent boy to a fault and likes to tease him about sexual subjects.

Lala Satalin Deviluke
She is good friends with Lala and likes groping her breasts. She often gives her wrong and lewd ideas to her questions.

Mio Sawada
Risa's friend, she also enjoys groping girls' breasts and whispering in their ears.

Haruna Sairenji
Risa's friend, whom she occasionally gropes along with her friend Mio, sometimes saying they've "grown".