We're New at This(2018)

Mijuku na Futari de Gozaimasu ga

Ikuma Saeki finally married his childhood friend and the girl of his dreams, Sumika. But while years of pining came easily to him, physical closeness does not...and he's having trouble navigating the intimacy that comes with marriage. Sumika, too, is having trouble bridging the gap between friend and lover...what is this innocent couple to do but navigate it together, awkwardness and all!

(Source: Kodansha USA)