On June 30, 2009, Yoshi Tatsu joined the ECW brand. He had his first match that night, defeating Shelton Benjamin, although he lost a rematch to Benjamin on the July 9 episode of ECW. On the October 20 episode of ECW, Tatsu defeated Zack Ryder to become number one contender for the ECW Championship, although he failed to win the championship the following week against Christian. On the December 22 episode of ECW Yoshi Tatsu defeated Jack Swagger to earn a spot in the ECW Homecoming battle royal where the winner would challenge Christian for the ECW title at the Royal Rumble. On the January 12 episode of ECW, however, Tatsu was not able to win the battle royal when he was eliminated by Kane. At the Royal Rumble, Tatsu competed in his first Royal Rumble match, but was eliminated by John Cena. Tatsu then formed a tag team with Goldust and the duo became the number one contenders for the Unified WWE Tag Team Championship, but failed in capturing the titles on the final episode of ECW on Syfy.
After the ECW brand was discontinued, Tatsu made his debut on the Raw brand on the February 22, 2010 episode of Raw, where he teamed up with Evan Bourne and Kofi Kingston to defeat The Legacy (Randy Orton, Ted DiBiase, and Cody Rhodes), after Orton turned on his partners. Tatsu won a 26-Man Battle Royal in the dark match to open WrestleMania XXVI by last eliminating Zack Ryder. In July 2010, Tatsu would be involved in a few backstage brawls with The Nexus to try to help John Cena get rid of them, which he failed to do. Yoshi then went to Japan to promote the new WWE SmackDown vs. Raw 2011 video game. After months of not appearing on WWE television, Tatsu returned on the November 11 episode of WWE Superstars, defeating Zack Ryder. On the November 29 episode of Raw, Tatsu teamed with Mark Henry to defeat WWE Tag Team Champions Justin Gabriel and Heath Slater, after a distraction by John Cena. A week later, Tatsu and Henry received a shot at the titles in a Fatal-4-Way Elimination Tag Team match, which also included The Usos and Santino Marella and Vladimir Kozlov. Tatsu and Henry were the first team eliminated in the match. On the February 14th episode of Raw, Maryse and DiBiase were about to kiss but instead Maryse kissed Tatsu. On the 24 February episode of Superstars during the match between Daniel Bryan and Ted DiBiase, Yoshi Tatsu came out and gave Maryse flowers but Maryse hit DiBiase with the flowers before Bryan used the LeBell Lock on DiBiase, making him tap out allowing Bryan to win the match.
On April 26, Tatsu was drafted to the SmackDown brand as part of the 2011 Supplemental Draft.
Tatsu was a WWE Pro for the fifth season of WWE NXT, also known as NXT Redemption, with his rookie being Byron Saxton. On the April 26 episode of WWE NXT, Tatsu was attacked by Saxton after Tatsu cost his match against Lucky Cannon. This would cause tension between the two until the May 17 episode of WWE NXT, where Tatsu would defeat Saxton. On the May 31 episode of WWE NXT, Saxton was the second rookie eliminated.
After Saxton's elimination, Tatsu began a feud with fellow NXT pro Tyson Kidd, whose rookie was also eliminated. Their feud stemmed from Kidd breaking Tatsu's toy figurine of himself and stealing one of the toy figurine's legs. Both wrestlers would trade wins during their series of matches, and Tatsu claimed back the stolen figurine leg by winning a Necklace on a Pole match on the July 26 episode of NXT. After the match, Kidd brutally assaulted the right leg of Tatsu, causing Tatsu to be absent from NXT for more than a month.
However, in the next few weeks, a mysterious Japanese symbol would appear on the TitanTron to distract Kidd during his matches. The symbol turned out to be the Kanji lettering for "pride” – a message from Tatsu. Tatsu returned on the September 6th episode of NXT, where he debuted black tights emblazoned with Kanji characters and the Japanese flag, had his small lock of blond hair dyed red and had half his face painted. Tatsu would go on to defeat Kidd on that episode to end the feud. Tatsu later explained that his new look and wrestling style was due to him wanting to better portray Japanese culture, Japanese pride and the aggressive style of Japanese wrestling; he also explained that his face paint was a tribute to The Great Muta. Tatsu would stop wearing his facepaint to the ring by October 2011.
Meanwhile on NXT, Tatsu would form an alliance with Trent Barreta; from December 2011, they feuded with Curt Hawkins and Tyler Reks. Both teams would play pranks on each other, with Tatsu being locked in a closet and Reks' hands being superglued onto an Xbox controller. At the Royal Rumble, Tatsu defeated Heath Slater in a dark match.
On January 24 Tatsu would team up with Santino Marella to form a comical, the pair could not decide what the tag team should be known as, Santino suggested "Santoshi" and Tatsu suggested "Yoshitino". The pair took on the WWE Tag Team Champions Primo & Epico in a losing effort. On next weeks episode of SmackDown, Santino stated that the combination of the two was not suitable and therefore searched for another partner which would be Hacksaw Jim Duggan. At Over the Limit 2012, Yoshi competed in a People Power Battle Royal and was unsucsessful. Yoshi would then go on a losing streak for the rest of 2012, losing to Hunico, Tensai, Damien Sandow, Wade Barrett and The Miz. On the January 23, 2013 episode of NXT, Tatsu and Percy Watson entered a tournament to crown the first NXT Tag Team Champions, but were defeated by the Wyatt Family (Luke Harper and Erick Rowan) in the first round. He later suffered a torn rotator cuff in his shouder.Then, Tatsu ended his losing streak when teamed up with Ezekiel Jackson to defeating Hunico and Camacho at Wrestlemania Axxess on April 4th, 2013. In his TV appearance, Tatsu suffered another loss to Jack Swagger on April 10, edition of Main Event. On April 16th episode of Main Event, Yoshi Tatsu entered a battle royal where the winner would compete against Wade Barrett for the Intercontinental Championship but got eliminated, and was eventually won by Justin Gabriel. On May 29, edition of NXT, Tatsu competed in 18 Men Battle Royal for #1 Contender of NXT Championship, but got eliminated by Mason Ryan. Tatsu then mainly made sporadic appearances on NXT throughout the rest of 2013. He returned to action in March 2014 on NXT, where he was defeated by Corey Graves. Tatsu was also one of the 31 WWE Superstars featured in the Andre the Giant Memorial Battle Royal during WrestleMania XXX and was the first one eliminated by The Great Khali.
Tatsu was released from his WWE contract on June 12, 2014.