Aiyoku no Eustia -Original CharacterSong Series- St.IRENE，LAVRIA / LICIA
| Composed by | 藤井亮太 |
| Arranged by | 藤井亮太 |
| Published by | Side Connection Music |
| Catalog number | SCMN-010A |
| Release type | Game Soundtrack - Official Release |
| Format | 1 CD - 6 tracks |
| Release date | April 22, 2012 |
| Genres |
| 1 | HIKARIのノクターン |  | |
| 2 | Buds Crown | | |
| 3 | HIKARIのノクターン(Off vocal) | | |
| 4 | Buds Crown(Off vocal) | | |
| 5 | HIKARIのノクターン(光のノクターン -philia instrumental-) | | |
| 6 | Buds Crown(Buds Crown -dolce instrumental-) | |
