Question about Muramasa in Eromanga-sensei

Does anyone know, from original LN perhaps, why Muramasa's right hand is bandaged? She is manifestly left-handed.

UPDATE: J. thinks her bandages are related to her calligraphy practice, which I suspected too, but I don't see exactly how it works.

UPDATE: The reason is spelled out in manga ch.34 and it's too dumb for me to reveal here. Suffice it to say, it's nothing sensible like calligraphy. The anime wisely omits that reveal, although it occurs within the time frame covered by the adaptation. {The manga compensates in the next scene by a more natural handling of the Hana's fan letter than anime managed.}