After the anime series A Couple of Cuckoos, Season 2 got a new trailer, visual and character last week, one thing I kept seeing popping up in conversations on various online forums I belong to was the ‘pentagon romance’ in the drama.
As, apparently, I am sometimes a little obtuse, I had no idea what a pentagon romance meant. (Yeah, I kept thinking about the U.S. Department of Defense headquarters. Sue me).
Even though, I do know a pentagon has five sides.
So, after doing quick research, here is what I found out about pentagon romances — something that is often talked about by Japanese media and Japanese anime fans — just in case you were a bit confused as well.
What is a pentagon romance?
A “pentagon romance” (五角関係, gokaku kankei) is a term used in Japanese media (especially when it comes to manga, anime, and light novels) to describe a love polygon involving five people.
It is usually used when multiple characters have conflicting romantic feelings for each other. Feelings that then create a complex web of relationships.

How it works in A Couple of Cuckoos
The first season of the anime is about a somewhat messy “love square” (four people) at first, but when Nagi’s childhood first love, Ai, arrives in the upcoming Season 2, it will escalate into a pentagon romance.
And, when it does, five characters in the anime will then be emotionally involved.
The five people in A Couple of Cuckoos involved in a pentagon romance
- Nagi Umino (protagonist) – Engaged to Erika (switched-at-birth pair), who he now has feelings for.
- Erika Amano – His arranged fiancée but also now has feelings for Nagi.
- Hiro Segawa – A classmate possibly in love with Nagi, although she is also engaged to someone else.
- Sachi (Nagi’s adoptive sister, Erika’s biological sister) – Has a brother-complex that has moved into romantic feelings.
- Ai (Childhood first love of Nagi) – A new entrant in Season 2 who is about to stir up even more chaos.
So, why use “Pentagon”?
It’s a term that emphasizes the scale of the comedy/drama — ie: more rivals, more misunderstandings, and more hilarious or tense moments.
Think of it as a love triangle on steroids.
And yep, with what went on in Season 1 of A Couple of Cuckoos, and with what is apparently about to go down in Season 2 when Ai arrives, things are already complicated and about to get worse.
And so, now you know, eh?
As for Season 2 of A Couple of Cuckoos, the anime is scheduled to premiere some time in July, 2025.

Freelance writer of all things K-drama, K-pop and manwha, with manga thrown in. New reader of manhwa, but motoring through them at a crazy rate. Probably should have been born Korean.