Note from the series itself:
"Microwaves: Renchin is a portmanteau of two Japanese words:
One is a wasei eigo (a Japanese word that originated in English) word - renji レンジ which means microwave, and one is 'chin' - the sound that a microwave makes. In every day conversation, the Japanese usually use the word chin to refer to microwaves.
However, the Kanji in the title is a homophone (it's pronounced 'ren') the same as the ren in renji, but here, the kanji means 'romantic love.
A cute and fun Japanese play on words!"
Not licensed in English. Has been in hiatus for years in COO after volume 2, according to Manga Updates.
Edit: MU now says complete at 2 volumes, not sure if more was planned and canceled or what.
Series info:
https://www.mangaupdates.com/series/kpytq9f/renchin
1st: 8/17/22, 2nd: 7/28/25
Renchin!