[5] In 2019, he starred in Yuki no Hana ("Snow Flower"), a romance film based on Mika Nakashima's famous song of the same title.

[6] In 2017, he debuted as a soloist with the digital single "Wasted Love", while remaining a member of Sandaime J Soul Brothers.

He quit his job after 6 months and started to work as a shop assistant at an apparel store in Daikanyamachō, Shibuya.

[19] Though he was always fond of singing, he considered being a singer a dream too unrealistic to achieve, and therefore preferred a future as a hairstylist.

When he was studying at Kubota Barber Beauty College, Takahiro passed the Vocal Battle Audition 2006: Asian Dream and became a vocalist of Exile.

[18][20] In February 2010, Tosaka participated in Exile presents Vocal Battle Audition 2: ~Yume o Motta Wakamono-tachi e~.

Since he had not received professional vocal training or sung in public before, he was called the "Cinderella Boy without Experience" during the audition.

[24] On November 10, Tosaka made his mainstream debut as member of Sandaime J Soul Brothers with the single, "Best Friend's Girl".

His first solo song under his name, "CHAIN BREAKER", was released in High&Low Original Best Album and was about his character Hiroto Amamiya.

[50] He also featured in a few songs of Takahiro's band Ace of Spades, including "SIN", "TIME FLIES", and "THE RED RAIN, which were all about the Amamiya Brothers and were used as soundtracks in the High&Low series.

[51][52] On July 27, 2017, Tosaka made his solo debut with the digital single "Wasted Love", produced in collaboration with DJ Afrojack who had previously worked together with Sandaime J Soul Brothers.

[53][54] Previous to his solo debut, he also featured in Sandaime's member CrazyBoy (Elly)'s song " OZ Monster feat.

[1] On January 26, 2018, he released his third digital single "Luxe", featuring Sandaime groupmate CrazyBoy(Elly).

[59] He also featured in Honest Boyz(a hip-hop unit led by Sandaime's leader Naoto) 's single "BEPPING SOUND feat.

[66] In 2019, Tosaka starred in Yuki no Hana("Snow Flower") as Yusuke Watahiki, a romance film based on Mika Nakashima's famous song of the same title.

[8][9][10] In March he released the live footage of his Hiroomi Tosaka Live Tour 2018 "Full Moon" concerts at Saitama Super Arena, which took the first place on Oricon's weekly DVD, BD and joint DVD/BD ranking at the same time with about 59.000 copies sold in the first week.

[69][70] On April 10, Tosaka released his first physical single "Supermoon", which also contained "Blue Sapphire" and have one version of its cover drawn by Gosho Aoyama.

[72][73] The music video for the title track "Naked Love" was shot in Los Angeles and stars Tosaka alongside American actress Lauren Tsai.

On July 20 and 21, Tosaka held his first solo overseas concert in Taiwan titled Hiroomi Tosaka Taipei Concert 2019 Supermoon ~Under the Moonlight~, 3 years after he visited the island for the first time for an overseas premiere of the film High&Low The Red Rain.