You might like 'Horimiya'. It shares similarities with Shikimori in terms of character dynamics and the light-hearted tone. Both show the growth and interactions of the main characters in a school setting.
The ending of the Shikimori manga is quite satisfying. The main characters reach a conclusion that feels right for their journey, and loose ends are neatly tied up.
Some of the side characters like Shikimori's friends might also gain popularity in the fanfiction. If the fanfiction gives them more depth and interesting storylines, readers could really get attached to them. For example, a friend who has a hidden talent or a mysterious past.
Another plot could be a time - travel scenario where Shikimori goes back in time and has to deal with her past self and the challenges that come with it. This could add a whole new layer of complexity to her character.
The unique characters make it popular. Shikimori herself is a very interesting character with her cool and cute sides. Her relationship with her boyfriend is also quite charming, full of sweet and funny moments.
You need some graphic design software like Adobe Photoshop or Illustrator. Learn their basic tools and functions for manipulating images and adding effects.
Editing comics can be tricky. You might want to start by scanning your hand-drawn pages. Use tools to clean up lines, add shading, and adjust the colors. Also, make sure the text is clear and legible.