[2] Ito had won six ITF Futures events in Asian countries, and started to play mainly in ATP Challenger Tour since 2008.

In August, Ito claimed first challenger title in his career at Brasília by beating Izak van der Merwe in the final.

In later season, Ito earned men's singles bronze medal in 2010 Asian Games at Guangzhou, winning over defending champion Danai Udomchoke of Thailand in quarterfinals.

In April, Ito claimed his third challenger title in Recife after Tiago Fernandes withdrew before the finals, and he entered world's top 150 for the first time, climbing to no.133.

He took part in the Japan Open, and defeat Dudi Sela with three sets to proceed to the second round before losing to Australian Bernard Tomic.

He received wildcard for 2012 Australian Open, and advanced to second round of the major tournaments for the first time, beating Italian Potito Starace with four sets.

In March, Ito broke him into the top 100 for the first time, winning the Kyoto Challenger title by beating Malek Jaziri in final.

In spring clay court season, Ito reached the second round in Houston, winning over fellow Japanese Go Soeda.

[3] In grass court season, Ito reached the round two in Queen's Club, and made his first ATP quarterfinal in the UNICEF Open.

He reached quarterfinal in the Kremlin Cup to mark his career-high ranking world No.60, beating Roberto Bautista Agut and Konstantin Kravchuk.

After falling to 31st seed Martin Kližan in the 2015 Australian Open first round, he made it to final in the Hong Kong Challenger, being beaten by Kyle Edmund.

Ito bounced back from the failure to qualify for the Wimbledon by reaching the quarterfinal in Newport, defeating seventh seed Steve Johnson and Noah Rubin.

In March, he won all his matches in the qualifying tournament of the Miami Open and recorded his first Masters main draw win after beating Nicolas Mahut in straight sets.