Spoilers but we do these little playlist sections!!! So you'll find out soon enough for Fufie and Auntie 
But the song Coco has used for her Lorekeeper, Yu'Chri (who chronicles her adventures and worships her).
This is her theme song for her best friend (I'll be posting the english lyrics here)
Goodbye Sweet Pain
さよなら Sweet Pain
The night I rested my face on it will end with yesterday.
頬づえついていた夜は 昨日で終わるよ
I want to confirm
確かめたい
I opened my eyes in the darkness and thought about the meaning of meeting you.
君に逢えた意味を 暗闇の中 目を開いて
The sound of rushing shoes on the emergency stairs
非常階段 急ぐ靴音
I want to echo in the sleeping world
眠る世界に 響かせたい
A fallen bike in the corner of a vacant lot
空地のすみに 倒れたバイク
I'm looking up at the graffiti on the wall
壁の落書き 見上げてるよ
I'm sure it's true sadness
きっと本当の 悲しみなんて
It's something you can heal by yourself
自分ひとりで癒すものさ
I'm starting to understand My Revolution
わかり始めた My Revolution
To disrupt tomorrow
明日を乱すことさ
I want to tell someone
誰かに伝えたいよ
My Tears My Dreams Now
My Tears My Dreams 今すぐ
If you want to chase your dreams
夢を追いかけるなら
Don't cry easily
たやすく泣いちゃダメさ
you taught me
君が教えてくれた
My Fears My Dreams I can run
My Fears My Dreams 走り出せる
Feel it Heart Ache
感じて Heart Ache
The more you smile, the harder the nights are when you're alone.
笑顔が多いほど ひとりの夜がツライね
I want to share
わけあいたい
The words I wrote in the gaps in my textbook are starting to move
教科書のすき間に書いてた言葉 動き出すよ
homesick lovers
ホームシックの恋人たちは
I only believe in humor.
ユーモアだけを信じている
I run out at the intersection, but
交差点では かけ出すけれど
I get excited when you wave my hand
手を振る時は キュンとくるね
The strength to feel alone
たったひとりを感じる強さ
I don't want to get lost in the city
のがしたくない 街の中で
I want to seek My Revolution
求めていたい My Revolution
It's about changing tomorrow
明日を変えることさ
I want to tell someone
誰かに伝えたいよ
My Tears My Dreams Now
My Tears My Dreams 今すぐ
own way of life
自分だけの生き方
no one can decide
誰にも決められない
I want to stare at you
君と見つめていたい
My Fears My Dreams I want to hug you
My Fears My Dreams 抱きしめたい
I'm starting to understand My Revolution
わかり始めた My Revolution
To disrupt tomorrow
明日を乱すことさ
I want to tell someone
誰かに伝えたいよ
My Tears My Dreams Now
My Tears My Dreams 今すぐ
If you want to chase your dreams
夢を追いかけるなら
Don't cry easily
たやすく泣いちゃダメさ
you taught me
君が教えてくれた
My Fears My Dreams I can run
My Fears My Dreams 走り出せる
She also references other media a lot like One Piece and Avatar. She's a bit of weeb so her listening to Japanese music only makes sense.
