Yukitaka and Shouichi Makise were good friends in college, under an influence and inspiration of a mentor. He will then sponsor on Shouichi's research. However he stopped the funding due to his own business crisis which results in the Makise family moving to Aomori.
Yukitaka died in a plane crash several years before the events of Steins;Gate. He was the only victim of the crash. However, his daughter later uses a D-Mail to save his life, by making him believe she was kidnapped and forcing him to take the bullet train instead. However, due to the D-Mail, the Rounders were able to approach him and take his IBN 5100, which he had received from Suzuha Amane.
His survival led to a world line where Faris is a RaiNetter and Akihabara is still an Electric Town instead of a moe hub. Faris later sent another D-Mail that led to Yukitaka's death, so that Rintarou could acquire the IBN 5100.
It was he who originally donated the IBN5100 to the shrine where the Urushibara family lives.