The Gamba Osaka player, who bade farewell to Bayern ahead of last night's friendly match with Holland, has agreed a one-year loan with Hoffenheim, starting in July.
"We will be more variable in our attack thanks to Takashi Usami," Hoffenheim coach Markus Babbel told the club website.
"He is ambitious, very agile and quick, and he is technically strong with a good shot on him.
"We are looking forward to having him here."
The Japan international struggled to make the grade at Bayern and was restricted to just three Bundesliga appearances and one in the Champions League.
He played 18 times for their reserve team, though, and found the back of the net six times, convincing former Bayern defender Babbel he still has a bright future in the Bundesliga.
"I want to make the breakthrough in the Bundesliga and I can only do that if I am playing," said Usami.
"I hope to earn chances to play at Hoffenheim and have the best possible success with the club."
Peniel Mlapa is leaving Hoffenheim, though, after signing a four-year contract with Borussia Monchengladbach for an undisclosed fee.