Imagine a Gacha Club character that was created by a player who then abandoned the game. This character was all alone in the game world. It had no purpose as the player who was supposed to guide its story was gone. It would watch other characters having fun with their players, and it just felt so left out and sad, like it was a forgotten entity in the Gacha Club universe.
One sad story in Gacha Club could be about a little cat - like character. This character had a dream of becoming a famous singer in the Gacha Club world. It practiced day and night, but when the big audition came, it got really nervous. And due to a technical glitch, its voice didn't come out right during the performance. Everyone laughed at it. After that, it lost all its confidence and hid away, too ashamed to face others again.
There's a fanfic called 'Gabimaru and Sagiri: The Unlikely Alliance'. In this one, they start off as reluctant partners but gradually form a deep connection. The author does an amazing job of showing Gabimaru's protective side towards Sagiri and how Sagiri comes to respect Gabimaru's skills and determination. It has some really intense and emotional scenes that make it a great read.
Characterization is key. A good Gabimaru x Sagiri fanfic should accurately portray their personalities. Gabimaru is tough yet has a soft side, and Sagiri is strong - willed and determined. If the fanfic can show how they complement each other, it's great. For example, Gabimaru's combat skills and Sagiri's strategic mind working together.
A common theme is the exploration of their relationship growth. Since they come from different backgrounds, fanfics often show how they overcome differences.