The brunette had begged Mina and Jihyo to let her come with them. They both said no. The latter reasoned out that she had to study and Momo would be back anyways. Mina supported that statement promising to update them everyday.

They were leaving for America in the next two days and would be staying there until Momo would have made a full recovery.
Their return date was quite unsure. It depends on when Momo would be fully alright.

Cerebral hypoxia doesn't seem that complicated but it is. Momo was losing control of her actions and the short term memory loss was getting worse as well. She couldn't even recognize Sana or even knew she was known worldwide.

It was a pain to see her like this but Sana knew she'd be okay, wouldn't she?