The Japanese attacker will finalise a move to Commerzbank-Arena with the newly-promoted side and compete in the Bundesliga just one year after arriving in Europe
The 24-year-old, who has four international caps for Japan, has agreed to join Frankfurt after the two clubs agreed on a reported €1.8 million deal.
The completion of the transfer will be finalised pending Inui passing a medical, which is expected to take place in the coming days.
Inui, who joined Bochum from Japanese side Cerezo Osaka last summer, had been linked with a new challenge after airing his wish to further his career at a bigger club during the season.
Frankfurt secured promotion to the top tier of German football after finishing second in 2. Bundesliga, two points shy of champions Greuther Furth.