こういうシチュエーションもいいですよね。後は
「妖夢ちゃん」って呼んで可愛がる鈴仙お姉さんと
「ちゃん付けやめろよ！（甲高い声）」と怒る妖夢君もいいと思うよ

I like this type of setup. After this, I'd want Reisen-oneesan to lovingly call out "Youmu-chan," and then Youmu-kun would respond (in a high-pitched voice) "don't call me -chan!"