When Itsuki and Chitose visit Amane's apartment for a Christmas party only to discover that the angel Mahiru lives next door, they instantly become very curious about the relationship. Chitose, obsessed with cuteness, insists on becoming friends with Mahiru. The day after Christmas, Amane notices that Mahiru has a fever. Despite Mahiru's stubbornness, Amane convinces her to stay and rest in his room. When Mahiru sees Amane so diligently taking care of her as if returning the favor she did for him that one memorable day, it seems to put her at ease.
I'm very glad to hear that. 
I guess happiness comes cheap.
أنا مسرورة جدّاً لسماع ذلك. أعتقد
أنّ تحقيق السّعادة سهل
Das ist sehr nett von dir, aber dann scheinst du
nicht viel zu brauchen, um glücklich zu sein.
Me alegro de oír eso.
Es sencillo hacerte feliz.
Me alegro de oír eso.
Es sencillo hacerte feliz.
Ça me fait chaud au cœur,
Mi fa piacere sentirtelo dire.
Allora la felicità può anche essere a buon mercato.
Estou muito feliz em ouvir isso.
Mas acho que sua felicidade sai bem barato.
Спасибо на добром слове. 
Как тебя легко осчастливить.