This year marks 30 years since I graduated from high school. I saw an old friend last night for the first time in 30 years. His father passed away a long time ago and his mother lives with him in Tokyo now. So he doesn't have a house to stay in anymore in this city. He was invited as a lecturer of the meeting sponsored by a pharmaceutical company. I held a welcome party with my high school classmates. He is a professor of Tokyo University in the Department of Medicine. It's honorable for us too. He is a person of dignity, but when we got together in a bar after his lecture, we got back to our high school days. Three hours had passed as quick as a wink. We held the key to seeing each other again.
hold the key to ～の鍵を握る、～を約束してくれる