[3] He didn't play at all in 2015 or 2016 before finding himself in Gamba's starting line up towards the back end of the 2017 season where he played a total of 7 league matches and 2 AFC Champions League games without getting his name on the scoresheet.
Gamba changed head coaches ahead of the 2018 season with Brazilian Levir Culpi replacing the long serving Kenta Hasegawa and this saw a big reduction in Takagi's top team playing time as neither Culpi nor mid-season replacement Tsuneyasu Miyamoto could find space for Takagi in their starting line-ups and he was restricted to a mere 1 J.League Cup substitute appearance against Urawa Red Diamonds.
[1][2] In 2016, Gamba's Under-23 side joined J3 League along with the reserve teams of FC Tokyo and Cerezo Osaka.
Takagi featured for them often in their inaugural campaign, netting once in 23 appearances as they finished 9th in the overall standings.
[1][2] In May 2017, Takagi was elected Japan U-20 national team for 2017 U-20 World Cup.