Masayoshi Son isn’t letting go of the reins at SoftBank Group Corp. anytime soon, even as the founder tells shareholders he’s taking the issue of his succession seriously.

Son, who has often indicated he plans to find his replacement in his 60s, may stay on as the chairman into his 70s, the billionaire told shareholders during their annual meeting Wednesday. Son may relinquish the chief executive officer title and hopes to have an idea of who his successor will be at around 69. For now, the 63-year-old CEO, unusually wearing reading glasses during his presentation, said he feels energized "thanks to advanced medical technology.”

Coming up with a plan for who will succeed Son is SoftBank’s biggest challenge, according to Yuko Kawamoto, who just stepped down as director after one year on the job. She had been the first female board member for the conglomerate and shareholders approved the appointment of another, Koei Tecmo Holdings Co. Chairman Keiko Erikawa, at the meeting.