When I introduce myself as “Oikawa,” people often ask, “Are you from the Tohoku region?” It’s true that both of my parents are originally from Iwate Prefecture. However, I was born in Mitaka, Tokyo, later moved to Kawagoe, Saitama, then to Hiroshima City, where I spent my junior and senior high school years. Afterward, I returned to Tokyo, and now I live in Yokohama, near my wife’s family home.
The surname Oikawa is neither particularly rare nor extremely common, falling into the category of moderately common surnames in Japan. It ranks 278th nationwide, with approximately 76,500 people bearing the name. This surname is most commonly found in the Tohoku region, particularly in Iwate and Miyagi Prefectures, where it is a familiar name in many communities.
One prominent theory regarding the origin of the surname is rooted in geographical features. “Oikawa” is thought to refer to the confluence of two rivers, originally known as “Aikawa.” Over time, this evolved into “Oikawa,” with families living near such locations adopting it as their surname.
The historical background of the surname is also quite fascinating. It is said to trace its origins back to the samurai lineage of the Seiwa Genji clan, specifically the descendants of Minamoto no Yorimasa, a prominent figure in Japanese history. This connection imbues the surname Oikawa with a sense of heritage, prestige, and pride linked to a noble lineage.
Today, the name Oikawa is both approachable and widely recognized, partly thanks to notable individuals who share the name. For instance, there’s the actor and musician Mitsuhiro Oikawa, affectionately known as “Micchi,” who, incidentally, earned me the nickname “Micchi” back in the day. Then there’s Nao Oikawa, a former adult film actress, and even a professional baseball player for the Hanshin Tigers, whose surname Oikawa is pronounced “Oyogawa.” On one occasion, I explained my name over the phone as “Oikawa – three strokes for ‘o’ and river,” only to receive mail addressed to “泳川” (Swim River) instead.
The surname Oikawa offers a rich connection to both regional and historical roots, which is part of its unique charm. For those who bear this name, delving into its geographical and historical origins can foster a deeper sense of identity and pride.