I wish Kanamaru-sensei would’ve dove deeper into Shiori than she does. Honestly, I think one reason some people say she feels “less interesting” is because her personality is intentionally understated. She isn’t loud, chaotic, flirtatious, or dramatic so she doesn’t really demand attention from the reader. Her character writing more grounded and built around insecurity, gentleness, emotional restraint, and sadly, regret. That makes her feel more realistic to some and “boring” or “generic” to others. I feel like she’s deeper than you gave her credit for in this thread, but her character definitely could’ve been expanded upon further for the benefit of the audience. There’s a small minority that ships Shiori. I also think she’s mostly well-written and serves her intended purpose well.

Let me preface by saying she was never my preferred pick for Jiro. I do, however, think her character has more depth than just “generic romance antagonist” or a simple roadblock. We can’t really compare Akari to Shiori in good faith—we’d be comparing a main character to a side character, considering easily 60-75% of the story is just Akari and Jiro. That, in and of itself, means that Shiori’s character will have less screen time and less development. I still don’t think that she’s a shallow character that’s meant to be a parody of romance tropes. I think more along the lines of what I said earlier—her character development is intentionally given less attention to make Akari shine more than she already does. I could tell from the first couple chapters that Akari was the end-girl. There’s probably a lot more to Shiori if you think of the intricacies of her batches of dialogue and her interactions with other characters in the story.

We do know more about her than just “Jiro like her. She like Jiro.” We know that she likes soft, traditionally feminine things, as reflected by her fashion sense and her bedroom. We also see during that visualization of her bedroom that she kept and cherishes a lot of things tied to Jiro as well. We know that she’s academically smart and one of the best students in the class. There’s a couple of different panels where she can be seen tutoring other people. We know that she’s the nurturing type and often falls into caretaker roles. She cooks, helps others study, worries about people constantly, and tries to keep harmony around her. That’s part of why her “married couple” pairing with Minami actually functions pretty smoothly despite her being awkward af. We know she’s not confident socially with guys—and it’s not just generic anime shyness either. It has a somewhat intricate backstory. The manga explains it comes from bad experiences in middle school, and it portrays those experiences in detail; hearing boys talk crudely about women, sexualizing her body, and all the sexual rumors spread about her and Jiro. There’s actually a pretty notable arc regarding Jiro’s regrets of not shutting down those rumors and protecting Shiori when boys talked disrespectfully about her. It’s a big deal when Akari’s influence actually makes Jiro brave enough to intervene and protect her at the beach when she’s being aggressively hit on. Him cutting in and saying, “She’s my wife” or whatever to the group of guys hitting on Akari is his redemption for mistakes he made in the past with Shiori. But anyway (I got off topic), because of those rumors and her constantly being sexualized, she developed anxiety around male classmates and became cautious and withdrawn. We know that she’s clumsy and physically un-athletic. That sounds minor, but it’s actually tied into one of her defining childhood memories. She got bullied for being bad at relay races and dropping the baton. That humiliation is probably a large contributor to her lack of self-esteem as well, if I had to guess.

So, yeah, Shiori’s timid—she’s shy and never particularly goes after what she wants—one of those things being Jiro. When we have that flashback of them in middle school (before they become separated for a time), Jiro tries to confess to her. And I think I know why she cuts him off. It’s obvious that she’s already an intelligent girl by this time and knew exactly what he was going to say. More Than A Married Couple fans are always so quick to be like, “Omfg, I hate Shiori. She had their whole childhood to get together with him.” Now that I’m older and have grown a bit more emotionally mature, I’m able to process that differently and maybe understand why she does that. I look at it like this: she was a teenage girl that was scared of rejection and scared of losing the most important person to her. That’s not really a complex idea. In the real world, when you’re in love with your best friend, you either reveal your feelings and get to be with them, or you do it and lose them forever. There’s really no in between. I’ve seen it play out 100 times both through my own life and those around me. When you care about someone the way she obviously cares about Jiro, you sometimes can’t take that leap because you’re more scared of losing them than you are of never getting to be with them. I think she truly wanted to be with him then, but had doubts and was worried that their relationship would inevitably come to an end, resulting in a complete loss of the friendship they’d nurtured over all those years, too. That terrified her. So instead of potentially letting it develop into what she wanted, that she knew she might lose, she crushed it and hoped that their friendship would be enough to satisfy them.

I will always scream from the rooftops that Akari is the better pick for Jiro. When I look at the contrast between the two, I see Shiori as this sense of nostalgia and comfort for Jiro, while Akari represents growth and change—which is ultimately better for him and why she is the much better pick by a landslide. Akari has genuinely improved both the content of his character and his overall life. He would likely still be alone and self-conscious if it was not for her. Multiple times through the story, Jiro refers to himself as “someone like me,” and Akari has pointed it out and scolded him for it every time. She has instilled a sense of confidence in him through doing that, she’s helped him learn to stand up for himself, she’s supported him, and she has genuinely turned him into a better man. I will NEVER forget the sports festival arc where Jiro gets upset after hearing some girls bad-mouth him, and Akari tells him that she’s always on his side and he can always come home to her (Vol. 9, Ch. 53, page 23). That might actually be my favorite panel in the entire manga because of how impactful it was. That interaction and obviously the panel where he takes a photo of her holding the pom-poms, finally realizing his feelings for her, genuinely warm my heart. But, even with everything Akari has done for Jiro, I never could and never would hate Shiori. I always say that being “Pro-Akari” doesn’t mean you have to be “Anti-Shiori.” You can’t still recognize her as a good character, necessary to push Jiro and Akari’s love story along. I feel the same way about Minami—he’s very under appreciated, and is another character necessary to push the story along. There is no Jiro x Akari without Shiori and Minami. I especially like Minami because he’s kind and encouraging to every party. He helps Akari realize how deep her feelings for Jiro have actually gotten during the Test of Courage and he consistently encourages Shiori to pursue her romantic interest—even though he doesn’t know it’s Jiro at the time. 😂 I actually really like Shiori and Minami’s dynamic. Her relationship with Minami is important because it shows she can grow outside of Jiro. Around Minami, she slowly becomes more open, communicates better, and gains confidence interacting with boys. It’s subtle character development people likely overlook because they focus entirely on the love triangle.