Listen.....
Billy Corgan wrote Tonight, Tonight for two reasons. As a homage to his favorite band (Cheap Trick) and as an encouragement letter to himself after surviving a nightmare childhood. Corgan's father was a talented professional musician, and also a mentally unstable petty criminal and deadbeat. His mom was divorced from dad and wasn't a major presence, and his stepmother was (allegedly) physically and emotionally abusive to him and his brothers. Corgan eventually taught himself how to play the guitar, and got the hell out of there to become a musician.
Boring bio data aside, the choice of THIS song for this chapter has to be deliberate. Suddenly it recasts some otherwise inexplicable aspects of Mitsuki's life:
-Why is she living with her uncle, of all people?
-When Kanna invited her uncle to live with her in the USA, he declined because he wouldn't leave Mitsuki behind. That implies that he isn't her legal guardian, and if he left she would either be placed in a state orphanage or worse.
-When Kanna reappears years later, she is trying to entice Mitsuki to move to the States upon her graduation, is it because she's offering a fresh start with an entire ocean between the girl and her problematic past?
-The Mangaka shows some understanding of US immigration policies, and familiarity with the H2B visa.