This was done by other group, but there are missing translations.
Naho's little speech bubbles:
私が。。。連れてきたから。。。こんな"Because I... brought her here... this kind of thing..."
犬丸君に何て言ったらいいの。。。
"What should I say to Inumaru-kun...?"
Sayaka's letter:
「七星たん へゼッタイ鬼碑忌先生を見つけてね
大好きだよ 私がもし死んー
きをおとさないで
れいのうたんてい
ずっといっし」
"Dear Naho-tan
You must definitely find Kibiki-sensei, okay?
I really love you. If I should die ----
Don't be discouraged.
*reads "Spiritual Detective", so it might mean she's reminiscing about being a Spiritual Detective along with Naho, or cheering Naho, the Spiritual Detective*
---We'll always be together---"
