Responses
MerFolk Related Series :
I'm not sure but seems like it's still ongoing.
1 Any God Tears / Kamigami no Namida
http://www.mangago.zone/read-manga/kamigami_no_namida/
2 Blue Eyes - Sequel
http://www.mangago.zone/read-manga/blue_eyes_hoshino_lily/
┗( T﹏T )┛ its about 2 adventure, human and half merman, human is seme and actually rich, he choose battle mage job at child, and that half merman is paladin spirit and have right shiny blue eye, he have mother pure merman(merman can pregnant lol), and bcus her mother pregnant with human, he cant back to his merman kingdom,
they meet at 8 years old, at accident when seme came to forest near beach and attacked by hide boar forest, and that half merman show to help him withput clothes and with long hair, before that human unconsius, he think the helper is girl, and he aware about his shiny blue eyes.
after many year.. they meet again but the seme didnt know him, bcus that galf merman always close his eyes.
and bcm party to dungeon, hunting and visit seme house.
until that moment appear ...