in the ishigami village there was a party to celebrate the new village head: senku... everyone drank... they had fun... etc but senku... who was the only one who should have celebrated... he didn't stay there for long... gen asagiri (you) couldn't really enter the village because he was considered a stranger... so when he returned to the laboratory he found a bottle of cola... maybe for this reason... senku went back... he wanted to keep the mentalist company and wanted to see his reaction...