In the end, Ryan decided to stay for the rest of the day and spend the night in Tokyo as well. It would be stupid to leave without receiving the tome. Considering how useful it would be, Ryan also decided to help Yahiko with the celebration. As long as he doesn't have to give speeches and smile to everyone, he would stay and celebrate… not like everyone would be able to understand his words.
"I should have asked him to give me the tome in order to level up," Ryan said while he was watching the citizens of the city preparing for the party. "in any case, this is a good opportunity for me… I have almost a full day to think about what I should do next."