Another theme is the idea of them being partners in some way, either in battle or in solving problems within the Soul Society or the human world. They might have to rely on each other's strengths and overcome their differences. In many fanfictions, they start off not getting along very well but then gradually develop a deep bond. This is also a very popular theme as it allows for a lot of character development and relationship building throughout the story. It's really interesting to see how they change and grow closer over time.
The fanfiction 'Snow and Sun' is also great. It focuses on how Hitsugaya's cool and collected nature contrasts with Ichigo's fiery passion, and how they start to influence each other over time.
One great place to start looking for Ichigo x Hitsugaya fanfiction is on Fanfiction.net. There are numerous stories there with different themes and plotlines. Some might focus on their unlikely friendship turning into something more, while others could be set in alternate universes where they have different relationships than in the original series.
You can start by searching on popular fanfiction websites like FanFiction.net or Archive of Our Own. Just type in 'Toshiro Hitsugaya x Ichigo' in the search bar and you'll get a list of relevant stories.
Adventure and teamwork is also a theme. Since they are both part of the Soul Society in the Bleach universe, fanfictions sometimes put them on missions together. Through these shared adventures, their relationship deepens, and they rely on each other more, which in turn leads to the development of their romantic relationship.
One common theme is friendship. Given their relationship in the original Bleach series, many fanfics explore the deep bond of friendship between them in different scenarios. Another theme is adventure. They might go on adventures together, facing various challenges.
One common theme is loyalty. Their loyalty to each other, whether it's through thick and thin in the Soul Society. Another theme is growth. They often grow as individuals and as a pair in these fanfics.
Friendship is a very common theme. Hyourinmaru and Hitsugaya have a special bond as a zanpakuto and its wielder. Fanfictions often explore how this bond deepens over time, through shared experiences and challenges. For instance, they might face a difficult enemy together and their friendship becomes stronger as a result.
One aspect of Toshiro Hitsugaya x Momo Hinamori fanfiction is the emotional depth. Since they have a long - standing connection, fanfictions may play with the idea of unspoken feelings. Maybe Hitsugaya has always been secretly protecting Hinamori, and in the fanfiction world, these feelings could be more openly explored. It could also involve Hinamori realizing her true feelings for Hitsugaya after some sort of event that makes her see him in a new light.