Pink Mermaid Series by Haru Akebono

Highly recommended by Ruri Miyahara, the creator of The Kawai Complex Guide to Manors and Hostel Behavior and Love Lab! Rune, an “ex”-mermaid, has come out from the ocean to be with the human she’s been pining for, Riku, her first love. But as fate would have it, she finds out that she'll never be able to become one with a human…?! This is the first volume of a sexy, yet pure, romantic comedy that's a bit risqué, and sure to make you laugh out loud!

Rune, the ex-mermaid, is roomies with her first love, the human boy named Riku. But whenever she tries to be intimate with him, her mermaid tail comes back, becoming a daily struggle for the two! Packed full of romance, volume two of this sexy but pure love story is sure to make you smile!!

Rune used to live on the ocean floor with the other mermaids. Now she's living on the surface with Riku, her first love. If she can be with a human, she'll turn into a real girl...but when things start getting steamy, her legs turn back into tail fins. The bond between Riku and Rune grows stronger by the day, but time's running out for their interspecies love story. Don't miss the final volume!