In many mangas, the relationship between a neighbor and a cousin can be quite complex. Sometimes they are just casual acquaintances, while in other cases, they might have a deeper connection or shared experiences.
You should first have a clear understanding of the rules and limitations of the healing magic system in your manga. If you don't, it's easy to misuse it.
In amputee fiction stories set in a secret garden, the garden can offer different challenges and experiences that aid in healing. For instance, the character may have to navigate through difficult terrains in the garden with their amputated limb. This struggle can represent their real - life battles, and as they overcome these challenges in the garden, they also grow stronger and heal on a psychological level. The plants and animals in the garden can also act as companions and sources of inspiration for the amputee, furthering the theme of healing.
One big challenge could be dealing with cultural references and idioms that might not translate easily. Also, maintaining the style and tone of the original manga can be tough.