Hanabi catches a cold, but both Iori and Konomi have to go to school, so Sonoa is left to take care of Hanabi. But Sonoa has some quirks to her personality, and things don't quite turn out as expected when she tries to take care of Hanabi.
Yeah, we talked about how she's 
like an older sister to me.
Ja, wir hatten’s davon, dass sie
wie eine ältere Schwester für mich ist.
Sonoa parecía mi hermana.
Sonoa parecía mi hermana.
Oui, on aurait dit
une grande sœur.
Sonoa è come una sorellona per me
 e gliel'ho anche detto.
Foi, falamos muito sobre como
ela é uma Onee-chan para mim.