Oiwa was influenced by comic books, art, and magazines throughout his youth, as well as the urban environment of his birthplace.

Oiwa held his first solo exhibition while he was still in college and soon after participated in the 21st São Paulo Art Biennial (1991).

[2] Throughout his career, he has participated in art globally, beginning in the city of his birth, then relocating to Tokyo in 1991 after graduating from university.

[8] During the summer of 1989 at the age of 23, he created Whale1 and Whale 2, highlighting the juxtaposition between reality and illusion of his works during this period with the creation of a painted virtual image of detailed depth on flat Kraft paper.

It proved to be a valuable learning period, not only as an opportunity to live in Europe but to study European oil paintings in museums, but he was unable to become accustomed to London.

He re-established his studio in Williamsburg, Brooklyn, and after initially applying to competitions without results, with greater intensity against competition, he focused his energies into the production of his art and in conjunction with meeting people over time, his efforts over time finally reaped their benefits.

[15] There is often a perspective from above, with Oiwa often choosing to depict his idea in large paintings that employ a bird's eye view, or drawing method, from his foundation in architecture and characteristic and many of his works, but also to focus on what is overlooked.

[16] Oiwa also observes and depicts current day events and social issues in his artwork through his lens and experiences.

This are evident in works such as his Gardening series, colorful landscape paintings with multitudes of flowers floating above the cityscape with an underlying themes of nature, urbanization, and war in a layered narrative as well as many other.

Behind the fascination Oiwa's works awaken in so many people is the originality and breadth of vision with which he connects these innumerable elements – their amplitude, in other words.