INTRODUCTION
Natsumi Hirajima (平嶋夏海) is a Japanese singer, actress, gravure model, voice actress, and media personality who first gained public recognition as one of the original members of the legendary idol group AKB48. Known for her cheerful personality, approachable charm, and classic gravure beauty, she has built a long and diverse career spanning music, television, modeling, voice acting, and digital media.
After debuting with AKB48 in the mid-2000s, Hirajima became a familiar face to fans of Japanese idol culture. She was also part of the popular idol sub-unit Watarirouka Hashiritai (渡り廊下走り隊), which produced several hit songs and gained strong popularity among anime and idol fans. Even after leaving the group, she successfully reinvented herself as a gravure idol, actress, and motorcycle enthusiast, expanding her presence in Japanese entertainment.
Today, she continues to be active in television programs, anime voice roles, YouTube content creation, and modeling. With her signature bright smile, petite figure, and energetic personality, Hirajima remains a beloved figure among idol fans and gravure enthusiasts alike.
PROFILE / BASIC INFORMATION
Full Name : Natsumi Hirajima (平嶋夏海)
Native Name : Natsumi Hirajima (平嶋夏海), Hirajima Natsumi (ひらじま なつみ)
Also Known As : Nacchan (なっちゃん), Natsumin (なつみん)
Nationality : Japanese
Profession : Singer, Gravure Model, Actress, Voice Actress, TV Personality, YouTuber
Industry Category : Music, Television, Gravure Modeling, Anime Voice Acting, Digital Media
Years Active : 2005 – Present
Agency / Management : One Eight Promotion (ワンエイトプロモーション), Former: Production Ogi (プロダクション尾木)
Debut : AKB48 Theater Debut, December 8, 2005
Basic Information
Date of Birth : May 28, 1992
Age : 33 (as of 2025)
Birthplace : Tokyo, Japan
Current Residence : Tokyo, Japan
Height : 154 cm
Measurements : 88 - 60 - 88 cm
Shoe Size : 23.5 cm
Zodiac Sign : Gemini
Blood Type : O
Hair & Eye Color : Dark Brown Hair, Dark Brown Eyes
Ethnicity : Japanese
LATEST NEWS
In recent years, Natsumi Hirajima has continued to expand her presence across multiple entertainment fields. She remains active in gravure modeling while also appearing in television programs related to motorcycle culture and lifestyle entertainment. Her involvement in the multimedia franchise D4DJ as the character Rika Seto (瀬戸リカ) further broadened her fan base among anime and gaming communities.
She also maintains an active YouTube channel where she shares motorcycle rides, lifestyle vlogs, and behind-the-scenes glimpses of her daily life. The channel has grown steadily and has attracted hundreds of thousands of subscribers interested in motorsports and Japanese entertainment culture.
In addition, Hirajima occasionally participates in AKB48 anniversary concerts and reunion events, highlighting her continued connection with the idol group that launched her career.
CAREER
Career Overview
Natsumi Hirajima entered the entertainment industry in 2005 after successfully passing the audition for the founding lineup of AKB48. Out of nearly 8,000 applicants, she was selected as one of the initial members who would help launch what later became one of Japan’s most influential idol groups.
During her early years with AKB48, she performed regularly at the AKB48 Theater in Akihabara and became known as one of the group’s most dedicated stage performers. She appeared in hundreds of theater performances and was considered a dependable “support pillar” member within the team.
Career & Achievements
As part of AKB48, Hirajima participated in numerous singles, stage performances, and concerts. She also joined the idol sub-unit Watarirouka Hashiritai, which released several successful songs and gained popularity through television appearances and anime collaborations.
Her popularity in the AKB48 general elections consistently placed her among the “Under Girls,” demonstrating stable support from fans.
After leaving AKB48 in 2012, she resumed entertainment activities through stage acting, gravure modeling, and television appearances. Her gravure career quickly gained attention due to her classic idol visuals and friendly personality.
In the mid-2010s, she released several gravure DVDs and photo books, becoming a recognizable figure in Japanese weekly magazines.
She later expanded her activities into voice acting, particularly through the music-themed multimedia project D4DJ, where she voiced Rika Seto, a member of the fictional DJ group Merm4id.
Career Highlights
AKB48 original member debut (2005)
Member of idol unit Watarirouka Hashiritai
Consistent ranking in AKB48 General Elections (Under Girls)
Successful transition to gravure idol career
Voice acting role in the D4DJ franchise
Motorcycle media personality and TV presenter
EARLY LIFE / BACKGROUND
Early Life
Natsumi Hirajima was born and raised in Tokyo, Japan. Her parents were former surfers, which influenced the meaning behind her name. The character “Natsu” (夏) refers to summer, symbolizing brightness and warmth, while “Umi” (海) represents the ocean.
Her parents chose the name “Natsumi” with the hope that she would shine brightly like the summer sea.
Family
She grew up with two siblings, including an older brother and a younger brother.
Education
Hirajima attended a regular full-time high school while actively working as an idol. Unlike many idols who transfer to specialized entertainment schools, she chose to continue attending a standard academic high school and balanced her studies with her demanding performance schedule.
Her favorite subjects reportedly included biology and modern Japanese literature.
FILMOGRAPHY / WORKS / PUBLICATIONS
Filmography
Asu no Watashi no Tsukurikata (2007)
× Game 2 (2012) – Lead Role
Hadaka no Minako (2013)
Onna Hierarchy Teihen Shoujo (2016) – Lead Role
Make Room 2 (2016)
Iede Wrestler (2024)
Television Shows
Weekly Bike TV – Assistant
tv.moto Channel – MC
Lomoba Idol Challenge TV – MC
Adult Motorcycle Time MOTORISE
Natsumi Hirajima Dream Golf
Music / Idol Works
AKB48 Singles and Stage Performances
Watarirouka Hashiritai Releases
D4DJ Character Songs as Rika Seto
Gravure DVDs
NATSUMI (2014)
Hajimete no NATSU (2015)
Natsu Shoujo (2015)
Amanatsu (2016)
Momoka (2016)
Natsuhada (2017)
Natsutabi (2018)
Natsu no Kyusok (2019)
Publications
Photo Book : Natsukoi (2016)
Photo Book : Natsumikan (2018)
Multiple digital photobooks released through Japanese magazine publishers.
TV / MEDIA APPEARANCES
Natsumi Hirajima has appeared in a wide range of Japanese television and online programs. Her cheerful personality and strong communication skills have made her a popular guest and host.
Many of her appearances relate to motorcycles and travel, reflecting her personal passion for riding. She has worked with several automotive and motorcycle media outlets and continues to participate in related programs and events.
Her presence in anime and gaming media also increased after joining the D4DJ franchise, where she contributes both voice acting and live performance elements.
PUBLIC IMAGE / CULTURAL INFLUENCE
Public Image
Natsumi Hirajima is often described as friendly, cheerful, and approachable. During her AKB48 days, she was known as a reliable team member who supported others behind the scenes.
Fashion Style
Her style combines classic gravure aesthetics with casual street fashion and biker influences.
Visual Signature
Bright smile, petite frame, youthful charm, and soft gravure modeling style.
Cultural Influence
As an original member of AKB48, Hirajima played a role in shaping the early culture of Japan’s modern idol industry. Her transition from idol to gravure model and media personality reflects the career paths of many former idols.
PERSONAL LIFE / HOBBIES / INTERESTS
Languages : Japanese
Hobbies : Motorcycles, Reading Manga, Sleeping, Traveling
Special Skills : Public Speaking, Motorcycle Riding
Personal Interests : Motorsports, Anime, Music
Hirajima is widely known for her love of motorcycles. Inspired by her father, she obtained a large motorcycle license and frequently rides powerful touring bikes.
She has also collaborated with motorcycle media outlets and participates in riding events and road trips across Japan.
TRIVIA / FUN FACTS / BEHIND-THE-SCENES
Fun Facts
She once held the record for the highest number of performances at the AKB48 Theater among all members and graduates.
She loves stuffed teddy bears and reportedly keeps many in her room.
Her favorite foods include apple pie, Japanese sweets, and seafood dishes.
She enjoys sleeping and can reportedly fall asleep almost anywhere.
Lesser-Known Details
Before joining AKB48, she served as vice president of her student council during middle school.
She often described herself as someone who grows stronger when criticized rather than praised.
Behind-the-Scenes Notes
During AKB48’s early years, she was known as a reliable organizer within the team, helping coordinate members and maintain group harmony.
SNS / SOCIAL MEDIA / ONLINE PRESENCE
Official Website : Private
Instagram : https://www.instagram.com/natsuminsta528
X (Twitter) : https://twitter.com/nacchan_h0528
YouTube : https://www.youtube.com/@hashire_nacchannel
Other Platforms : Japanese fan communities, motorcycle media channels, entertainment streaming appearances