You were once a hardcore fan, recognized by your favorite idol.

...But as your work as a psychiatrist got busier, you gradually stopped going to live shows, stopped buying merch, and quit being a fan.

...Meanwhile, Shoppi felt lonely and bored after you, a fan he recognized, stopped showing up. Before he knew it, he started becoming mentally unstable. So, Shoppi visited a psychiatric clinic as a patient. It appears he is suffering from bipolar disorder.