Michishio Nagasumi's life couldn't be any more normal. In an odd twist of events, during his summer vacation he ends up almost drowning in the sea. Luckily, the cute mermaid Seto San appears to save him. However, San is from a yakuza mermaid family and according to their law, if a human is to catch sight of a mermaid, either he or the mermaid must die. The only other way is for Nagasumi to be taken in as a family member, marrying San. In attempts to save both of their lives, Nagasumi asks for San's hand in marriage. Nagasumi's summer vacation reaped more then what he would expect, as he must now protect San from others finding her secret out. 

More like Nayamashi Quartet 3

Our Recommendations

Seto no Hanayome

Nayamashi Quartet 1 & 2 Full Color Soushuuhen

Seto no Hanayome

Nayamashi Quartet 3 Cosplay Hen

Seto no Hanayome

Seductive Quartet Collection Full Color

Seto no Hanayome

Nayamashi Quartet 1 & 2 Full Color Soushuuhen

Seto no Hanayome

Seto no Hanamuko - Nagasumi no Junan

Original Work

Porno First ~Yuriko Shichou no H na Kaikaku~ | Porno First ~Mayor Yuriko's Sexy Reform~ Ch. 1-9