Hey guys, I just found some cute AR in the manga
Poro no Ryuugaku-ki, also known as
Demon Prince Poro Diaries.
Hell if I know the context, but chapter 15 has Poro's friends (male and female) be accidentally transformed into babies by some magic, and Poro has to take care of them. No process, unfortunately, but it does leave them in oversized clothes and looks adorable.
http://www.mangaraw.live/poro-no-ryuugakuki-chapter-15