Fujita Maiko (藤田麻衣子) - Mune ga Atsui (胸が熱い)

Single by Fujita Maiko. It serves as the ED song for the game "白華の檻 ～緋色の欠片4～ 四季の詩"

This song is a limited release and is being sold digitally only.

Song is available for sale on the following:
- iTunes / mora / music.jp / dwango.jp / musicbus

I'd recommend iTunes for those who aren't from Japan. Just search the iTunes store by copying and pasting "藤田麻衣子" (Fujita Maiko's name in Kanji) and you should get a list of songs available for sale.