In page 9 there is a small panel that shows something out of character for someone as energetic as Yan: He's tired. I think he's overwhelmed and he doesn't belong there so going true by his words, he already said it would be 2-3 days he can keep the number of customers so the restaurant will need to change to keep those customers coming. The 'bloodshed' he advised on meant he needs to leave permanently otherwise the staff would only be overshadowed by Yan, a man past his prime who's only there to revive the restaurant. Sustaining it's success needs to come from it's core staff. Inoue has been the center of the past few chapters because he's a head who is overshadowed by a man who is his superior but unlike Yan, he has the privilege of youth which means he can catch up to him and has what it takes to sustain the restaurant's momentum.