16-year-old high school student who discovers he was switched at birth. He initially meets Erika while heading to his biological family, but they decide to cohabitate and explore a relationship to avoid separation.
Core sibling relationship providing domestic stability and emotional grounding.
A confined, high-stakes moment that accelerates emotional vulnerability between the contract partners.
Nagi uncovers Ai's hidden motives, altering their previous understanding and creating narrative tension.
Domestic integration where Hiro and Nagi navigate new family dynamics to redefine their shared life.
Hiro's abduction triggers an immediate rescue mission, cementing their bond beyond romantic tension.
A paternal relationship where Nagi gains life lessons and uncovers household history.
A sibling dynamic shaped by shared domestic responsibilities and external relationship pressures.
Rituko directly opposes Nagi, using psychological games to disrupt their plans and test their resolve.
Mutual support during make-up exams and morning study sessions strengthens their daily routine.
A standard mother-son bond complicated by gift-giving struggles and shared household care.
Ai's true purpose targets Nagi's past, creating tension and driving S2's central mystery.
Explore the full interactive character relationship map of A Couple of Cuckoos