What are some “unflattering” names that aren’t kirakira names?

I've been working in Japan for a while now and making short films in my spare time.

I've been trying to make a film with a female character nicknamed "Momo" but I'd like her real name to be something unusual or old sounding (like the name 'Loretta' sounds strange nowadays). Bonus points if the name begins with 'Mo'

I haven't met enough people in Japan to get a feel for rare names yet and would appreciate any help or resource you guys could give!