Merry Valentine’s for everyone!
Here Valentine’s day is actually a day for Friends and Friendship, not for romance or couples. Friends give each others little gifts as token for the friendship.
So, go forth and cherish your dear friends, whether they’re real, animals or the fictional characters you love!
What comes to marine biology au, mermen give special gifts for their loved ones, like spouse and family members. Usually the gifts are things they find drifting in the waters or gotten lost into bottom of the waters (jars, glass bottles, bottle caps ect.) or something pretty from nature; pebbles, sea shells, plants, feathers.
Because Haru lives pretty near the shore, he finds all kind of interesting things forgotten, lost or left behind by humans. He gave Makoto a piece of mirror, while Makoto found a little bracelet which was dropped from some swimmer down to the bottom of the sea.