Yoku Wakaranai keredo Isekai ni Tensei Shiteita You desu

I am cute, but I was a middle-aged researcher in my previous life?! Surviving in another world with magic and sciences!! The orphan Ren was riding the carriage after being sold, when she got involved into an accident, and got her previous life's memories back! "I was... a middle-aged man!" Indeed, s