Yuuta Segawa starts his first year in college. He meets second year Raika Oda under unusual circumstances thanks to Sako and Nimura of the Street Observation Research Society. Meanwhile, Yuuta bumped into Raika again had a uneasy conservation with her and as she left he starts to have a crush on her. After joining the Street Observation Research Society for 3 months, he meets up with his sister and misinterpreted him with seeing Raika. His sister asked him to visit Sunday to see her kids. However, it turned out into a babysitting task for the kids while they are out for awhile which his sister neglected to say. His conversation with his nieces were quite awkward.
大学入学を機に、一人暮らしを始めた瀬川祐太。
美人で巨乳の二年生・莱香に惹かれ、路上観察研究会、略して「ロ研」に入部するなど、新生活は順調に思えた。
夏のある日、姉の祐理から大事な用事があるからと呼び出される。
女手ひとつで育ててくれた姉の頼みを断われず姉夫婦の家に向かうと、夫婦はそろって不在！
かくして祐太は中学生の空、小学生の美羽、保育園児のひなと留守番するハメになる。
신입생 환영회 때 필름이 끊긴 유타를 몰아붙이는 한 남자 선배. 하지만 피해자를 자처하는 미인 선배는 왠지 발연기 느낌이 나고...신입 확보 작전이었음이 뽀록난 덕에 무사히 노상 관찰 연구회라는 괴이한 서클에서 탈출하게 된다.
Yuuta Segawa starts his first year in college. He meets second year Raika Oda under unusual circumstances thanks to Sako and Nimura of the Street Observation Research Society. Meanwhile, Yuuta bumped into Raika again had a uneasy conservation with her and as she left he starts to have a crush on her. After joining the Street Observation Research Society for 3 months, he meets up with his sister and misinterpreted him with seeing Raika. His sister asked him to visit Sunday to see her kids. However, it turned out into a babysitting task for the kids while they are out for awhile which his sister neglected to say. His conversation with his nieces were quite awkward.
