The striker, who only graduated two weeks ago from Keio University after completing an economics degree, represented Japan during the Asian Cup in January and has retained his place in the squad under new coach Vahid Halilhodzic.
The bid from the Blues is reported to be around ??4m and a spokesman for the Japanese club said: “It is true that we have received an official offer from Chelsea for Muto. But nothing has been decided.”
The new J-League season started last month and Muto has impressed, notching three goals in his first four appearances to help Tokyo sit third. He struck 13 goals last year and was named in the J-League’s best XI.
Muto told the Japanese press: “I’m honoured to receive an offer from this wonderful team, but I have not made any decision yet.”
Chelsea, who have a seven-point lead in the Premier League with only eight games remaining, recently announced their ‘largest ever commercial deal’ with Japanese tyre firm, Yokohama Rubber Company.
Japanese players have struggled to make an impact in the Premier Leaue in recent years, with Muto’s international team-mate Shinji Kagawa rejoining Borussia Dortmund after a difficult spell with Manchester United.
Maya Yoshida has battled to hold on to a first-team role at Southampton, while Tadanari Lee left the south coast club last year after failing to make a lasting impression.