Takakuwa, a former Uratex Dream import, dropped six points while Ibeh was unstoppable with her seven markers and five rebounds to take home the Tournament Most Valuable Player honors as Shinjuku secured the $3,000 cash prize.
"We fought from the beginning until the end and I'm very happy that we got the win and I got to show my skill," said the Nigerian center who admitted it was her first time playing 3x3 basketball.
She was joined in the Mythical Three by Uratex Dream's Renzhu Li and CT Tigers' Kiri Endo.
Mizuno Naho added four points as Milai Mori sealed the triumph with a booming corner deuce with 1:31 to spare in this tourney.
It also completed a perfect run for the Givers after topping Pool A in day one and overcoming fellow Japanese team Maurice Lacroix, 14-9, in the quarterfinals and a thrilling 21-19 win over Endo and the CT Tigers of Thailand in the semis.