After finding out her boyfriend Ren has a fetish for taller women and harems, Kasumi decides to use her metaverse powers to fulfill those desires on their next date. But along the way, she finds herself addicted to growing and multiplying endlessly. Looks likes Ren is gonna need caste Samarecarm a few times before this date is over.

Sites:
https://www.furaffinity.net/user/jjz-godd/
https://www.pixiv.net/en/users/22267255