Yoshinori Muto gave the J-League outfit a 31st-minute lead in Jeddah but Galeno levelled 17 minutes into the second half with a thunderous strike and Toney confirmed Al Ahli's progress eight minutes later with an inch-perfect finish.
The win takes Al Ahli into a second consecutive final and keeps Matthias Jaissle's side on track to become the first team since fellow Saudi Pro League side Al Ittihad to win back-to-back titles in 2005.
"We're really proud again to be in the final, back-to-back is something special and a huge honour and privilege," said Jaissle. "The game was not easy, as always in this stage, in a semi-final in this competition. Details decided the game."
The Japanese side took the lead when Katsuya Nagato's free kick from midway inside the Al Ahli half was nodded across goal by Yuya Osako to the unmarked Muto, who slid his shot past Edouard Mendy.
Al Ahli almost levelled with the first half in stoppage time, with Rayan Hamed heading Galeno's free kick from the right against the far post before Toney's attempt to flick in Enzo Millot's cross went narrowly wide.
Franck Kessie headed wide seconds after the restart and Toney saw his attempt ruled out for offside five minutes into the half as Al Ahli cranked up the pressure on the Japanese outfit.
Daiju Sasaki should have doubled Kobe's lead in the 54th minute when he was found unmarked inside the area by Mitsuki Hidaka but the winger crashed his shot against the crossbar.
However, eight minutes later, Al Ahli were level when Galeno unleashed an unstoppable strike from 25 yards that fizzed beyond the reach of goalkeeper Daiya Maekawa.
A further eight minutes later, Al Ahli were in front. Maekawa flapping at Galeno's cross from the left allowed Toney the time and space to slide his low finish past three Kobe defenders on the line.
Al Ahli will face either Shabab Al-Ahli from the United Arab Emirates or Japan's Machida Zelvia in the final with the pair due to meet on Tuesday.