One great 'Muichiro x Reader' fanfiction is 'A Meeting in the Mist'. It beautifully captures Muichiro's somewhat aloof nature while gradually developing a sweet relationship with the reader. The descriptive language used really makes you feel like you're in the Demon Slayer world with them.
First, get the right costume. Look for a bright yellow Pikachu onesie or make one yourself with yellow fabric and black accents for the ears, tail, and markings. Then, focus on the face. You can use yellow face paint to complete the look. Don't forget about Pikachu's rosy cheeks, which can be added with a bit of pink blush. Also, practice Pikachu's cute poses and expressions, like its shocked face or its happy hopping pose. This will make your cosplay more engaging and fun.
If the cosplayer traveled through the anime novels that they cosplayed, they might find some unexpected plots. For example, they might encounter their own characters and communicate with them. Or they might discover that something different was happening to their characters than they knew. In short, this kind of plot might surprise and excite them.
One common theme is the deep emotional bond between them. Given their relationship in the original work, fanfictions often explore how they support and care for each other on a more profound level. Another theme could be adventure, where they go on quests together and their relationship develops during those experiences.
The relationship development between Muichiro and the reader has to be believable. It can't be too rushed. A slow - burn, where they gradually get to know each other, understand each other's quirks, and form a deep connection over time is much more appealing. Also, the setting should be in line with the Demon Slayer universe. Whether it's in the Demon Slayer Corps headquarters or on a mission, the details of the world should be well - described.
Muichiro's death in the manga occurs during a particularly intense confrontation. His injuries accumulate, and he ultimately succumbs despite his valiant efforts.