Onii-chan Dakedo Ai Sae Areba Kankeinai yo ne
 

Not much but a 12 year old girl eyes a swim suit and imagines herself a couple years older wearing it.

Episode 8 4:00 http://tracker.anime-index.org/index...P+720&active=0

The anime centers around a high school guy living with his twin sister and female school mates all of the which are crazy about him.