The Tanuma Family Curse: The Secret Plot of Nagisa Kashiwagi and Tsubasa Explained
When most anime fans talk about Kaguya-sama: Love Is War, the conversation usually revolves around the legendary mind games between Kaguya Shinomiya and Miyuki Shirogane. And honestly, that makes sense. Their relationship is one of the best slow-burn romances in modern anime.
But after rewatching the series and rereading parts of the manga, I realized something: the most insane and strangely realistic relationship in the entire story is not the main couple at all.
It’s Nagisa Kashiwagi and Tsubasa Tanuma.
What started as a tiny comedy side plot slowly evolved into one of the wildest long-term storylines Aka Akasaka ever wrote. The deeper you look into it, the more obvious it becomes that this was never just background humor. It was deliberate foreshadowing from the very beginning.
And somehow, this “normal” couple ended up having the most dramatic future in all of Shuchiin Academy.
Why the Kashiwagi & Tsubasa Relationship Feels So Different
One thing that makes this subplot stand out is how fast everything happens.
While Kaguya and Shirogane spend entire arcs trying to survive emotional warfare just to hold hands, Tsubasa and Nagisa move through their relationship at terrifying speed.
That contrast is intentional.
Aka Akasaka basically created two versions of teenage romance:
| Couple | Relationship Style |
|---|---|
| Kaguya & Miyuki | Calculated, idealized, emotional |
| Nagisa & Tsubasa | Physical, impulsive, realistic |
And honestly, that’s why the Tanuma storyline feels so memorable. It’s messy in a way real teenage relationships often are.
The main couple represents fantasy.
Nagisa and Tsubasa represent consequences.
The “Tanuma Family Curse” Was Never Just a Joke
One of the smartest pieces of foreshadowing in the series is the infamous “Tanuma Family Curse.”
Fans initially treated it like a throwaway gag. But Aka Akasaka was planting seeds way earlier than most people realized.
The reveal comes through Tsubasa’s grandfather, Dr. Tanuma — the same doctor who examines Kaguya during her “love sickness” moments. He casually mentions something absurd:
- He became a father at 17
- His son became a father at 17
- The Tanuma men are apparently “efficient”
At first, it sounds like classic Kaguya-sama humor.
But manga readers immediately understood what was happening.
This was a loaded Chekhov’s Gun.
From that moment onward, every scene involving Tsubasa and Nagisa suddenly had hidden tension behind it. Their relationship stopped being “cute background comedy” and started feeling like a ticking time bomb.
And the craziest part?
The fandom predicted the outcome years before the manga confirmed it.
That’s the kind of long-term writing that makes Aka Akasaka such a dangerous storyteller.
Nagisa Kashiwagi Might Secretly Be One of the Scariest Girls in the Series
I think anime-only fans seriously underestimate Nagisa.
She looks sweet. She acts polite. She gives relationship advice. On the surface, she feels like one of the calmer characters in the cast.
But the deeper the story goes, the more obvious it becomes that she has an extremely sharp and possessive side.
In some ways, she’s actually more ruthless than Kaguya.
Why?
Because unlike Kaguya, Nagisa hides it perfectly.
There are multiple moments where she casually manipulates situations while maintaining her “nice girl” image. And her awareness of Maki Shijo’s feelings makes everything even darker.
She knows Maki loves Tsubasa.
She knows every PDA moment hurts her.
And yet she continues anyway.
That’s why this subplot feels psychologically heavier than people expect from a rom-com.
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Maki Shijo Is the True Victim of This Entire Story
If there’s one character the fandom collectively adopted, it’s Maki Shijo.
Maki’s suffering became such a meme because it’s painfully relatable.
She waited too long.
She never confessed.
And then she had to watch her best friend date the guy she loved.
Over and over again.
The series turns this into comedy most of the time, but beneath the jokes there’s something genuinely cruel about it. Some of the funniest scenes in the manga are also emotionally brutal if you stop and think about them for more than five seconds.
That’s why fans connected so hard with Maki.
She represents the side of romance anime usually ignores:
- Missed timing
- Emotional cowardice
- Regret
- Watching someone else get the future you wanted
And honestly, that’s probably more realistic than most anime love stories.
The Pregnancy Reveal Changed Everything
Then came the moment that completely exploded the fandom.
Nagisa Kashiwagi was revealed to be pregnant.
Even though fans had predicted it for years because of the Tanuma family setup, seeing it officially confirmed still felt surreal.
Because suddenly the joke became reality.
And this is where I think Aka Akasaka did something incredibly clever.
Instead of portraying teenage romance as endlessly idealistic, he showed that relationships can move too fast. Actions have consequences. Passion can completely change someone’s future.
That’s why the reveal hit harder than people expected.
It wasn’t just shocking.
It recontextualized the entire subplot.
Why Fans Still Talk About This Couple Years Later
A lot of anime side couples get forgotten after a season ends.
Nagisa and Tsubasa didn’t.
And I think there are a few major reasons why.
- The Foreshadowing Was Excellent
Fans love connecting old clues to later reveals. The Tanuma storyline rewards attentive readers constantly. - It Feels Weirdly Real
Compared to the exaggerated genius battles of the main cast, this relationship feels grounded in actual teenage impulsiveness. - Maki Became an Icon
The internet loves tragic characters, and Maki’s suffering turned her into one of the most beloved side characters in the fandom. - Tsubasa’s Transformation Is Hilarious
This random side character somehow “won” harder than almost anyone else in the series.
The fandom calling him the “God of Shuchiin” will never stop being funny to me.
Final Thoughts
The older I get, the more I think the Nagisa Kashiwagi and Tsubasa Tanuma subplot might secretly be one of the smartest parts of Kaguya-sama: Love Is War.
Not because it’s glamorous.
Not because it’s wholesome.
But because it feels human.
Messy relationships, jealousy, bad timing, emotional damage, impulsive decisions — this subplot quietly explored all of it while hiding behind comedy.
And somehow, a side couple that originally existed for relationship jokes ended up delivering one of the most unforgettable long-term payoffs in modern rom-com anime.
That’s peak Aka Akasaka writing.
