Level 70 Ichiban

Im trying to get the Like a Dragon Infinite Wealth platinum but Im almost giving up because of the Level 70 trophy. Im at level 60 now and everything I got to a new level the amount of xp needed to get to the next level increases. Im doing the vagabond method but I feel lile the last 10 levels Im gonna need 5 days to get to level 70, and Im already using the Kiwami drink to get 0,2x and two accessories that give me 1,4x. Is there anything else that could help me or just patience?