Yui is quite an interesting secondary character. Her cheerful personality contrasts with Hachiman's cynicism and Yukino's coldness, and she often acts as a mediator between them.
Hayato is another interesting one. His popularity and seemingly perfect image are in contrast to Hachiman's outcast - like nature. He also has an impact on the relationship between Hachiman and Yukino through his actions and words.
One of the main themes is self - discovery. Hachiman and Yukino both struggle with understanding themselves and their place in the world. Another theme is relationships, especially the complex relationship between them that evolves over the course of the story.
It's hard to say without reading it thoroughly, but perhaps there could be a detective - like character who is trying to uncover the secrets of Izaya and Namie. This character would add an element of mystery and suspense.
One interesting secondary character could be their classmate who is always getting into comical situations. This character might add some humor to the story and also serve as a contrast to the more serious or deep - thinking Hirano and Kagiura. For example, when Hirano and Kagiura are having an intense conversation about their future plans, this classmate might barge in with a silly problem, like losing their lunch box.
Yukino Yukinoshita is an important character. She is intelligent and has her own set of ideals. She initially has a somewhat cold exterior but gradually opens up as the story progresses. And there's also Yui Yuigahama, who is more of an outgoing and friendly girl. She often acts as a mediator between Hachiman and Yukino. These three characters form the core of the relationships and the story development in the 'Hachiman light novel' series.
One interesting scenario could be their first big argument as a married couple. Maybe it's over something as simple as how to decorate their new home. Hachiman wants a more minimalist style while Yukino has a more elaborate vision. This argument could lead to a deeper understanding of each other's needs and wants. Another scenario could be when they have to deal with a family emergency together. It shows how they support and rely on each other in tough times.
Shino is often an interesting secondary character in Naruto fanfiction. His ability to control bugs gives a unique aspect to stories. Writers can explore his more introverted nature and how it affects his relationships with other characters. Another one is Rock Lee. His determination and unique fighting style can be the focus. In fanfiction, his story can be expanded on, like his training methods and how he overcomes his limitations.
Well, Caster can be considered an interesting secondary character. He has his own brand of magic and his actions often disrupt the flow of the Grail War in unexpected ways. Also, Lancer is quite captivating. His loyalty and the code of honor he follows, even in the chaotic Grail War, add an interesting dimension to the story.
Snape is an extremely interesting secondary character for fanfiction. His double - agent role and his complex feelings towards Lily Potter can be explored from different angles. There are fanfictions that focus on his early years at Hogwarts, his relationship with the Marauders, and how all of that shaped him into the man he became. Another character is Cho Chang. Her relationship with Harry can be re - examined and extended in fanfiction, and she can also be given more depth and backstory outside of just her romantic connection to Harry.
Another theme is the exploration of their personalities. Since both Hachiman and Yukino have complex personalities, fanfictions may focus on how these personalities interact and complement each other. It could be about how Hachiman's cynical view and Yukino's cold exterior start to break down in each other's presence.
A good one often has in - depth character development. It should show the growth of Hachiman and Yukino's relationship leading up to the kiss. Their personalities, with Hachiman's cynical yet perceptive nature and Yukino's cold - exterior - but - warm - inside self, need to be well - portrayed.