Isekai ni Kita Boku wa Kiyoubinbode Subaya-sa Tayorina Tabi o Suru - Not exactly a carefree life, but everything else is present.
Reborn as my Love Rival's Wife - It's mostly just the average life of the two main characters living together. And they, for the most part, just act like best friends till later in the novel when the romance starts to progress.
Isekai Nonbiri Nouka Only Sense Online Nonbiri vrmmoki Isekai Yururi Kikou Angel in Online Manga wo yomeru Tensei Reijou wa Shomin no Aji ni Uete Iru
https://www.novelupdates.com/series/the-daily-life-of-the-immortal-king/ The only problem with this for you is the romance seems to have got lost at the moment but there are two candidates that have nor been developed yet(?)
COME ON GUYS ! No one recommend "Tensei Shite Inaka de Slowlife wo Okuritai" or in english "I Want to Live a Slow Life in the Countryside After Reincarnation" !????? Really slow life with a pinch of OPness + comedy. Recent chapters, there is a hint of romance by a friend noble of MC's father that says the rumors about a tsundere girl that closed her heart because her family neglected her because of her bad legs but turned around when they learned she had affinity with ice magic. 99% sure she will get together with MC later, if not i want to punch author for writing useless info.
I know I just recommended this novel, but I cant help it Martial Arts Master (I strongly recommend this one if you seek romance) Throne of Magical Arcana Lord of the Mysteries
Kuma Kuma Kuma Bear Isekai Yururi Kikou Isekai Izakaya Nobu Isekai Nonbiri Nouka Tensei Shite Inaka de Slowlife wo Okuritai An A-Ranked Adventurer’s “Slow-living” Nigotta Hitomi no Lillianne The Man Picked up by the Gods