Yoiyami Aketara Asobimashou is one of the songs performed in HakuMyu. It often accompanies Chizuru as a leitmotif, but is also heavily associated with her father, as well as her twin brother Nagumo Kaoru. The song was originally sung as a solo by Chizuru in Saito-hen.
In its original form, it represents Chizuru and her connection to her family and, by extension, her demon lineage. This melody is also used in a Minor-key variation that represents the Demons in general, and also Koudou Yukimura specifically.
| yoi ga fuketara | when the night comes | 宵が老けたら |
| nani wo shite asobimashou | what shall we play? | 何をして遊びましょう |
| oni nigyou ha mamemashou | let’s not play with the oni doll today | 鬼人形遊びはやめましょう |
| kowarete shimatte shikarareru | if it breaks we will be scolded | 壊れてしまってしかられる |
| yoi ga fuketara | when the night comes | 宵が老けたら |
| nani wo shite asobimashou | what shall we play? | 何をして遊びましょう |
| oni gokko ha ikaga jyarou | how about demon tag? | おにごっこはいかがじゃろう |
| mina ha oni jya asobe yasen | since we are all oni we can’t play | みなはおにじゃ遊べやせん |
| yoi ga fuketara asobimashou | when the night comes, let's play |
| nani wo shite asobimashou | what shall we play? |
| oningyou asobi wa yamemashou | let’s not play with the oni doll today |
| mikazuki detara asobimashou | let's play when the crescent moon comes out |
| oni gokko wa ikaga jarou | how about demon tag? |
| oni bakari ja asobeyasen | you can't play like a demon |
| tsuyu ga oritara asobu no wo yamemashou | let's stop playing when the rainy season starts |
| hi ga deru mae ni hayaku ouchi ni kaerimashou | let's hurry home before the sun rises |
| yoiyami aketara asobimasho nani wo shite asobimasho | let's play when the darkness comes, let's play anything |
| oni gokko wa ikaga jarou | how about demon tag? |
| oni ga detekite shu ni somaru | a demon comes every week |
| itsumo yasashiku yasuragi kureta | he was always kind and comforting to me |
| kowai yume wo mita yoru date | the night I had a scary dream |
| samishii toki mo samui fuyu demo | in lonely times and cold winters |
| itsudatte soba ni ite kureta | he was always by my side |
The melody also returns in several other songs, sung by Chizuru herself and thus becomes one of her main character themes in the HakuMyu musical series.