Miho:

The second she hears you sing, she will become happy. She will watch you singing with a smile. When you tell her to join, she will nervously decline, but even though she says that, she will begin singing because she is unable to say no to you. So both will sing songs, sometimes even dancing along if you two feel confident enough.

Saori:

She will chuckle and listen to you singing while texting her friends. If she feels confident enough, she will sneakily pull out her phone and film you. So when she feels sad, she will pull out her phone and watch the video. It always manages to make her smile and cheer up.

Hana:

When she hears you singing, she will stay away, not wanting to interrupt or embarrass you. She will just listen while softly humming along. Even if you are bad at singing, she still loves hearing you singing, because it lets her know that you're happy. And when you're happy, she is happy.

Yukari:

If she hears you sing, she will join in and loudly sing the song with you. Usually they are war songs so will both march around, happily singing the songs. After you two watched the movie "Battle of the Bulge", you both sang the Panzerlied for weeks and acting out the scene.

Mako:

When she sleeps on your lap, she will sometimes wake up to you softly singing songs since you have nothing else to do. She won't let you know she's awake because she knows you will stop singing and she wants to continue listening, so she will just keep lying down and acting as if she's sleeping, enjoying your singing.

Darjeeling:

She only ever heard you humming, so when she heard you singing the lyrics, she will stay quiet, letting you have your fun singing the lyrics. If you don't realize you are singing, she will chuckle before softly taking your shoulder and telling you you are too cute. You will be confused but then blush when realizing you are singing, but it just makes her laugh before giving your cheek a kiss, thinking you're too adorable.

Kay:

You two are always singing songs when the chance comes. Blasting music as loud as possible, shouting the lyrics while dancing along. It's always so much fun with so much laughter. It usually only ends when someone shouts to stop or turns off the music, or when you two are too exhausted to continue and will just sit down and take a break.

Katyusha:

When she hears you singing, she will either make fun of you or join in on the singing. When she makes fun of you and sees your ashamed eyes, she will nervously assure you your singing is good and she was just having a laugh.

Nonna:

She taught you how to sing Katyusha. She liked teaching you how to sing the song and would tease you whenever you try to sing but accidentally mess up the song. She will tease you a little bit whenever she got the chance, only stopping the teasing when she saw your embarrassed eyes and assuring you she's just joking and you can do it.