@keyjiii

To be able for him to get his diploma, Navi will re-enter school, leaving three toddlers home alone with his friend's best friend who he pleased to take care of the kids.

Miyu, an orphan and high school student have nothing in mind but to get a job to feed herself. She will take the job offered by Navi, thinking that it's just a simple babysitting.

Them being together for days was all fine, until she started showing them glimpses of their past.