There's a fixer in Street Legends, Tess Van Hama, who does a lot of work for MCT and "may" have connections to the people with the amount of shareholder juice who can make that happen. Use her to have the runners do whatever's necessary to convince Taiga to elect this person to the board.
Otherwise, you can always try convincing the Four Oyabuns to vote their shares for him.
Or Ryumyo ...