Yusaku Maezawa’s January 5 post, which has more than 4.6 million retweets, promised to randomly select 100 people who shared the tweet and followed his profile for a share in the £726,000 fund.
The entrepreneur, who Forbes said is worth about $2 billion (£1.57 billion), offered the prize after a new year’s sale from his online fashion retailer Zozotown made 10 billion yen.
Mr Maezawa, who first became famous as the drummer of punk band Switch Style, said he would message the 100 winners directly.
Mr Maezawa’s tweet overtakes previous top-spot holder Carter Wilkerson, who achieved viral stardom in 2017 with a bid to secure a year’s worth of free chicken nuggets from US fast food chain Wendy’s.
The teenager had posted a photo of the Twitter account for Wendy’s telling him he would need 18 million retweets for the year-long chicken supply, with the caption: “HELP ME PLEASE. A MAN NEEDS HIS NUGGS.”
With more than 3.5 million retweets Mr Wilkerson’s tweet knocked Ellen DeGeneres off top spot.
The talk show host’s star-studded selfie at the Oscars in 2014, taken by Bradley Cooper, had been the most retweeted tweet for three years.
The picture, which included Brad Pitt, Jennifer Lawrence and Meryl Streep, has more than 3.3 million retweets and was accompanied by the caption: “If only Bradley’s arm was longer. Best photo ever.”
Mr Maezawa’s sharp rise to top spot means former One Direction star Louis Tomlinson moves into fourth position with his 2011 tweet to Harry Styles.
In a post which has steadily increased to more than 2.6 million retweets, the singer wrote: “Always in my heart @Harry_Styles . Yours sincerely, Louis.”
Fifth position is taken by Spanish YouTube gamer Elrubius, who posted a prize giveaway similar to that of Mr Maezawa’s in August 2016.
The post, which reads “LIMONADA”, promised prizes to those that shared it and has more than 1.7 million retweets.
The change to the top positions also knocks Barack Obama out of the top five.
The former US president shared a picture of him interacting with some small children through an open window in 2017, with the caption: “No one is born hating another person because of the color of his skin or his background or his religion…”
The caption is a quote from the book Long Walk To Freedom, by former South African president Nelson Mandela, and the post has more than 1.6 million retweets.
It was announced last year that Mr Maezawa would become the first private passenger to be flown around the moon by fellow billionaire Elon Musk’s space exploration company SpaceX.
The amount Mr Maezawa paid for the ticket, which is set to take off in 2023, was not disclosed, but Mr Musk said that it was “a lot of money”.