Boku lost the One FC Lightweight Championship belt in a defeat via submission in Singapore but he will return to the cage on Friday at the Istora Senayan to take on Vuyisile Colossa in Champions & Warriors.
The 36-year-old Krazy Bee fighter, who is of mixed Korean and Japanese heritage, has scarcely given that fight much thought even if it represented one of the most comprehensive defeats of his career.
Renowned for his ready smile, it appears that Boku is only concerned with enjoying the twilight stage of his career and seems most preoccupied with making a late entrance into the featherweight division.
"I've totally forgotten about it [losing to Shinya] and don't care anymore. I'm staying positive and looking forward to fighting Colossa," he said at Max Metino's Warrior gym in Pasar Baru.
"Of course, I know my fans want me to get revenge and so I am training hard every day.
"But there's not much new informtion that I learnt [from that fight] although it was a turning point as it made me change my training programme and now I know how to become stronger.
"I haven't decided yet but when the time comes, I plan on changing to featherweight soon."
Andrew Leone's late pull-out due to injury means that Boku will once more headline a One FC event. A win could definitely serve to raise his profile and thrust his name back into the top of the lightweight field.
The Korean-Japanese man, however, is only taking it one fight at a time and is not fazed by 'the Cheetah', a nickname given to his opponent due to his speed of movement on the mat.
"Yes, I feel a bit lucky [to be in the spotlight again]!
"But I will fight just as hard if it was not the main event.
"I have only seen Colossa on the television a couple of hours ago today [Wednesday]. He seemed tough and determined.
"Even if he's called 'the Cheetah', my kicks are fast as well. I'm fine with whatever he brings to the cage."
Boku will find another Japanese champion in Koji Oishi in his path if he does choose to take part in the featherweight division, the latter having only recently wrested the belt off Philippines' Honorio Banario in May's Rise to Power event.
Image courtesy Joshua Irwandi