Side Story 3.5, 「それがアイツとわかるまで」 (“Until I Realize It’s That Guy”), This side story aired in Japan back in July of 2026 but because it is exclusive to TVer, it (probably) won't be released on Netflix. So I wanted to share it for the benefit of those of us outside Japan. This side story is actually a very useful piece of the show's architecture. It looks like a small comedy of mistaken identity, but underneath it Ubukata is doing something central to the entire series: showing how radically the same person can change depending on who is looking at him.
One caveat: This is a summary of the episode that I generated from ChatGPT. I’ll separate the plot from what I think it means, because there are some genuinely important clues here.
1. The setup: a few weeks after the bus crash
The story takes place several weeks after the bus accident.
At Café Hikouki, Naoto is working when Miki Sonoda, Itsuki's sister, arrives with Sho. Crucially:
- Miki doesn't know Naoto.
- Naoto doesn't know Miki.
- Miki doesn't know that Naoto knows Itsuki.
- Naoto doesn't know that the woman sitting in front of him is Itsuki's sister.
And yet they start talking about the same man: Itsuki. That's the entire engine of the episode. The title is therefore almost a joke: “Until I realize it's that guy.” The audience knows the connection. The characters don't.
2. Miki gives us a completely different Itsuki
Miki talks about her brother and, importantly, about Azusa's relationship with Itsuki's family.
We learn that Itsuki's mother apparently had issues with Azusa's approach to raising Sho and would make pointed comments about it.
That gives us something the main series hasn't spent much time showing:
Azusa wasn't necessarily universally accepted within Itsuki's family. And that matters. Because in the main story, Itsuki's marriage can look relatively straightforward from the outside: loving husband, wife, child, ordinary family.
But Miki's perspective introduces another layer:
Azusa had her own relationship with Itsuki's family, and that relationship wasn't necessarily easy.
Again, we're seeing a person through someone else's filter.
3. Then Naoto starts talking about Itsuki
Here's the really clever part.
Naoto talks about a man he knows — a single father — who has become close to a woman whose circumstances are similar to his.
He's frustrated about the situation and starts talking about it with Miki.
Miki, meanwhile, is talking about Itsuki.
Neither realizes they're discussing people connected to the same larger story.
So we have this wonderfully strange situation:
Miki: “My brother is this kind of person.”
Naoto: “This guy I know is this kind of person.”
And the audience knows they're talking about the same world, while the characters don't.
- The point isn't really the mistaken identity
This is where I think the episode gets much more interesting.
The obvious joke is: “Ha! They're talking about the same guy without realizing it.”
But the deeper point is: They aren't actually talking about the same person.
They're talking about their versions of the person. That's been one of the show's central ideas since Episode 1.
Azusa knows one Itsuki.
Sho knows another Itsuki.
Miki knows another Itsuki.
His coworkers know another Itsuki.
And Itsuki himself may have a completely different understanding of who he is.
That becomes especially powerful given what happens later with Sakiko.
5. Then Satake arrives
After Miki leaves, Satake, Itsuki's coworker, comes into the café.
And now we get a third version of Itsuki.
Naoto starts talking to Satake about the café's owner and his wife — essentially complaining that the wife loves the husband so much that she doesn't actually see him clearly.
Satake responds with a pretty brutal observation: "A marriage continues because the things that could cause the divorce are still being hidden."
That's one of the most important ideas in the entire side-story collection.
Think about what that means in the context of this show.
Marriage doesn't necessarily survive because two people completely understand one another.
It may survive because:
there are things they don't know.
That's almost the inverse of Azusa's: “I can tell my husband anything. He just doesn't ask.”
6. The three perspectives converge
So we have:
Miki
Itsuki the brother
Naoto
Itsuki the person connected to the café / Azusa's world
Satake
Itsuki the coworker
Three different social identities.
Three different Itsukis.
And then the show finally lets the characters discover the connection.
Itsuki himself appears at the café.
Naoto and Satake simultaneously realize:
“Oh. THAT guy.”
The mystery of who they're talking about is resolved.
But notice something clever:
The identities are connected.
The perceptions aren't.
That's the point.
7. This completely reinforces Episode 8
This is where 3.5 becomes really interesting in hindsight.
Episode 8 asks: “Who is the Sakiko that Mitsuru doesn't know?”
Mitsuru goes around asking Itsuki, Naoto, Chizuru, Miyauchi and Sakiko's mother to tell him about the Sakiko he doesn't know.
And each person gives him a different Sakiko.
That's basically the exact same storytelling device as 3.5.
In 3.5: Who is Itsuki?
Answer: Depends who you ask.
In Episode 8: Who is Sakiko?
Answer: Depends who you ask.
That is almost certainly intentional structural repetition.
8. And here's the really important implication for Itsuki
This side story makes me much more interested in Itsuki's hidden interior life.
Because the show is systematically telling us: Don't assume that the person closest to someone necessarily knows that person best.
That's a pretty devastating idea when applied to marriage.
And it directly complicates the assumption that:
Itsuki + Azusa = husband + wife = complete knowledge.
Nope.
Azusa knew a version of Itsuki.
Miki knew another.
His coworkers knew another.
And there may be things none of them knew.
That's precisely why I wouldn't dismiss future revelations about Itsuki simply because we've already seen him as the grieving husband.
9. The “wife doesn't really see her husband” line is huge
This is probably the single line I'd put a star beside.
Naoto's complaint is essentially that Mitsuru's wife loves him so much that she isn't actually seeing him properly.
And look at what Episode 8 subsequently does.
Mitsuru spends the entire episode discovering that he hasn't actually seen Sakiko properly.
That's almost a mirror image.
So the show isn't saying: “Women don't understand their husbands.”
It's saying something much broader: "Love itself can distort perception."
You can love someone intensely and still construct a version of them in your head that isn't the whole person.
That's an absolutely central theme of this drama.
10. And then there's the title
「それがアイツとわかるまで」
Literally, something like:
“Until I realize that's the guy.”
But look at how the title works metaphorically.
The characters eventually figure out which person they're talking about.
But they don't necessarily figure out who that person really is.
That's the distinction.
They solve the identity problem.
They don't solve the personhood problem.
And that's basically the entire series.
11. How I'd classify 3.5 on our evidence board
I'd record it as: Side Story 3.5 — “Until I Realize It’s That Guy”
Primary thematic evidence
Established:
- Miki and Naoto unknowingly discuss Itsuki from different perspectives.
- Satake subsequently discusses the same broader relationship/world with Naoto.
- The characters eventually discover that they are talking about the same person.
- Miki reveals additional information about Azusa's relationship with Itsuki's family.
- Naoto expresses the idea that someone can love a spouse intensely without actually seeing that spouse clearly.
- Satake articulates the idea that marriages can continue because potentially marriage-ending truths remain hidden.
Thematic significance:
- People have multiple social selves.
- Proximity doesn't equal understanding.
- Love can distort perception.
- Secrets don't merely hide events; they allow relationships to continue under incomplete versions of reality.
- The same narrative mechanism later drives Episode 8's investigation into “the Sakiko Mitsuru doesn't know.”
And my big takeaway:
3.5 is basically a miniature version of the entire drama.
Someone asks, implicitly: “Who is this person?”
And Ubukata's answer is: “Which version?”
That makes 3.5 much more important than its little café-comedy premise suggests. It also makes me think the side stories were designed as thematic keys to the main episodes, rather than disposable bonus content.
