OVA
Description
Michishio Nagasumi, an average and timid junior high school student, experiences a life-altering summer vacation at the Seto Inland Sea. After nearly drowning, he is rescued by Sun Seto, a mermaid from a yakuza family. Bound by mermaid law dictating execution for either witness or mermaid, Nagasumi agrees to marry Sun to save both their lives, thrusting him into the chaotic world of the Seto family.
Initially sensible and ordinary, Nagasumi reveals unexpected resilience against constant threats. His inherent ability to sense imminent danger manifests through his ahoge (cowlick), which stands upright as a visual threat indicator. This awareness grants him near-supernatural agility for evading attacks, a skill sharpened through relentless confrontations with antagonists like Sun's father, Gozaburo Seto, and the Seto Group's assassin, Maki. Despite enduring physical and emotional abuse, including assassination attempts and school bullying, he develops exceptional dodging capabilities and situational awareness.
Nagasumi's marriage to Sun evolves from convenience to genuine affection. He initially accepts the union for survival but gradually falls in love with her, openly declaring his feelings and proposing after she saves him a second time. Their bond strengthens through shared challenges, culminating in their first kiss. Sun's "Song of Heroes" enhances his physical abilities during conflicts. Nagasumi later learns to activate similar power-ups independently when Sun is threatened, demonstrating growing self-reliance.
At school, Nagasumi faces social isolation. Male classmates resent his relationship with Sun, while females blame him for inciting rivalries between Sun's and Lunar Edomae's fan clubs. This unpopularity persists despite his generally kind and calm demeanor. His home life is equally turbulent; his mother dotes on the Seto Group member Masa, leaving his father emotionally neglected. Nagasumi endures physical abuse from his parents, though his grandmother provides occasional stability and encouragement.
In the OVAs, set during his third year, Nagasumi continues managing external threats while navigating the overprotectiveness of Sun's and Lunar's fathers. His adaptability and resilience remain central as he mediates conflicts and protects those around him.
Initially sensible and ordinary, Nagasumi reveals unexpected resilience against constant threats. His inherent ability to sense imminent danger manifests through his ahoge (cowlick), which stands upright as a visual threat indicator. This awareness grants him near-supernatural agility for evading attacks, a skill sharpened through relentless confrontations with antagonists like Sun's father, Gozaburo Seto, and the Seto Group's assassin, Maki. Despite enduring physical and emotional abuse, including assassination attempts and school bullying, he develops exceptional dodging capabilities and situational awareness.
Nagasumi's marriage to Sun evolves from convenience to genuine affection. He initially accepts the union for survival but gradually falls in love with her, openly declaring his feelings and proposing after she saves him a second time. Their bond strengthens through shared challenges, culminating in their first kiss. Sun's "Song of Heroes" enhances his physical abilities during conflicts. Nagasumi later learns to activate similar power-ups independently when Sun is threatened, demonstrating growing self-reliance.
At school, Nagasumi faces social isolation. Male classmates resent his relationship with Sun, while females blame him for inciting rivalries between Sun's and Lunar Edomae's fan clubs. This unpopularity persists despite his generally kind and calm demeanor. His home life is equally turbulent; his mother dotes on the Seto Group member Masa, leaving his father emotionally neglected. Nagasumi endures physical abuse from his parents, though his grandmother provides occasional stability and encouragement.
In the OVAs, set during his third year, Nagasumi continues managing external threats while navigating the overprotectiveness of Sun's and Lunar's fathers. His adaptability and resilience remain central as he mediates conflicts and protects those around him.