Osako was born in Kagoshima City in the Kagoshima Prefecture of Japan, where his parents ran a ramen restaurant in Taniyama.[2] It was at this ramen restaurant that Osako began to play football, as he would often play with people from his neighbourhood who came to visit the restaurant.[2]
Club career
High school football
Having played football for children's teams Taniyama SSS and FC Sousarle, Osako enrolled at the Kamimura Gakuen Junior High School before moving on to the renowned football school, Kamimura Gakuen High School.[2][3] Settling immediately, he played a key role in his freshman year, with manager Maki Takemoto stating that if Osako hadn't joined the team, teammate Shio Fukuda would not have achieved the success he had - with Fukuda going on to join German side Borussia Mönchengladbach.[4]
In his second year at Kamimura Gakuen, he represented the high school at the 2021 All Japan High School Soccer Tournament, however they were surprisingly knocked out in the first round by the Teikyo Nagaoka High School [ja] of Niigata Prefecture.[5] This defeat motivated him, and he would later state "I never want to feel like this. I'll become more desperate, I'll be more greedy to win, and I'll definitely win in the end. I don't want to feel like this."[5]
The following year was a better one for Osako; having trained with the under-18 side of J1 League club Cerezo Osaka in early 2022, Kamimura Gakuen would go on to beat Cerezo Osaka in the playoffs of the Japan Club Youth Championship, earning promotion to the under-18 Premier League.[5] He was named captain of the high school team, and helped them to the semi-finals of the 2022 All Japan High School Soccer Tournament, where they were beaten by eventual champions Okayama Gakugeikan High School [ja] 4–1 on penalties after a 3–3 draw.[4][6]
Cerezo Osaka
Osako received an unofficial contract offer from Cerezo Osaka in February 2022, while only in his second year of high school.[2] Having officially joined the team in early 2023, he featured in a friendly against Hokushinetsu Football League side Fukui United on 26 February, where he played as a left-back, as opposed to his usual central midfield role.[7] Despite playing out of position, he earned praise from manager Akio Kogiku after the 4–0 win.[7]
His professional debut came two months later, playing in Cerezo Osaka's 4–0 J.League Cup loss to Kyoto Sanga, coming on as a late second-half substitute for Kakeru Funaki.[2] In June of the same year, he featured in the 5–0 Emperor's Cup win against Cento Cuore Harima, before suffering a knee injury which kept him out for a month.[8] In August 2023, he returned from injury, playing in a 10–3 friendly win against JFL side Maruyasu Okazaki.[8]
International career
Osako was first called up to the Japan under-15 side in March 2019 as part of the "04 group" - players born in 2004 - in preparation for the 2021 FIFA U-17 World Cup.[9] He featured at the Torneo Delle Nazioni, hosted in Italy in April 2019, playing in four games and scoring in Japan's 5–3 win against Turkey as Japan went on to lose to Mexico in the final.[10]
In June 2019 he was called up to the squad again ahead of 2020 AFC U-16 Championship qualification in September of the same year.[11] He established himself as a key member of the team, and was named captain for the qualification tournament.[12][13] He scored once against Malaysia as Japan finished top of their group, however due to the COVID-19 pandemic, the 2020 AFC U-16 Championship, as well as the 2021 FIFA U-17 World Cup, was cancelled. He was called up again in November 2019 for a tour of Spain the following month.[14]
^ abcde"大迫 塁 セレッソ大阪で歩み始めた18歳の原点 ～Next Stage 第3回～R" [Rui Osako's origins at the age of 18 at Cerezo Osaka ~Next Stage Part 3~]. nhk.or.jp (in Japanese). 12 April 2023. Retrieved 18 September 2023.
^"Rui Osako". cerezo.jp (in Japanese). Retrieved 18 September 2023.
^ ab"全3得点に絡んだ主将大迫塁 20メートルFK弾は「決められる気しかしなかった」 総監督は言い切る「大迫がいなかったら今の福田師王はいなかった」【高校サッカー神村3位】" [Captain Rui Osako, who was involved in all three goals, fired a 20-meter free kick, ``I had no intention of scoring it. The general manager declares, ``If it wasn't for Osako, Fukuda Shio wouldn't be where he is today. [Kamimura 3rd place in high school soccer]]. 373news.com (in Japanese). 8 January 2023. Retrieved 18 September 2023.
^ abc"「もっと死にものぐるいに」 神村学園MF大迫塁、停滞の時を経て最後の選手権に臨む" ["Be more desperate" Kamimura Gakuen midfielder Rui Osako faces his final championship after a period of stagnation]. soccer-king.jp (in Japanese). 30 December 2022. Retrieved 18 September 2023.
^"C大阪内定の神村学園MF大迫塁が見せた主将の落ち着き 青森山田との「ホコタテ対決」へ自信" [Kamimura Gakuen midfielder Rui Osako, who has been selected by Cebu Osaka, shows the composure of the captain and is confident in the “head-to-head showdown” with Aomori Yamada.]. football-zone.net (in Japanese). 3 January 2023. Retrieved 18 September 2023.
^ ab"Ｃ大阪ルーキーＭＦ大迫塁が左サイドバックで好プレー 小菊監督は高評価「大きな発見」ルヴァン杯で起用も" [C. Osaka rookie midfielder Rui Osako plays well at left back. Manager Kogiku praises him as a ``big discovery and may use him in the Levain Trophy.]. hochi.news (in Japanese). 26 February 2023. Retrieved 18 September 2023.
^ ab"【Ｃ大阪】MF大迫塁が母校・神村学園の応援で甲子園初体験 刺激を胸にJ1デビュー狙う" [[C Osaka] Midfielder Rui Osako experiences his first Koshien tournament while supporting his alma mater, Kamimura Gakuen, and aims to make his J1 debut with excitement in his heart]. nikkansports.com (in Japanese). 28 August 2023. Retrieved 18 September 2023.
^"【U-15代表】2021年のU-17W杯を目指す"04ジャパン"が欧州遠征を実施！20名のメンバーで国際大会に挑む" [[U-15 National Team] “04 Japan” aiming for the 2021 U-17 World Cup will conduct a European tour! Challenge an international tournament with 20 members]. soccerdigestweb.com (in Japanese). 16 April 2019. Retrieved 18 September 2023.
^"佐藤海空斗、岡本岳らがU-15日本代表候補トレーニングキャンプメンバーに選出" [Kaikuto Sato, Gaku Okamoto and others selected as training camp members for U-15 Japan National Team candidates]. saitama-soccer.jp (in Japanese). 25 June 2019. Retrieved 18 September 2023.
^"U-15日本代表の軸は技巧派MF「鹿児島の大迫」" [The core of the U-15 Japan National Team is the technical midfielder “Osako of Kagoshima”]. web.gekisaka.jp (in Japanese). 4 July 2019. Retrieved 18 September 2023.
^"[AFC U-16選手権予選]U-15日本代表のゲーム主将務めたMF大迫塁(4枚)" [[AFC U-16 Championship Qualifying] Midfielder Rui Osako (4 photos) who served as game captain of the U-15 Japan National Team]. news.infoseek.co.jp (in Japanese). 22 September 2019. Retrieved 18 September 2023.
^"スペイン遠征に向かうU-15日本代表メンバーが発表! 神村学園中MF大迫塁など20名が選出" [The members of the U-15 Japan national team heading to the Spain tour have been announced! 20 players have been selected, including Kamimura Gakuen Junior High School midfielder Rui Osako]. excite.co.jp (in Japanese). 22 November 2019. Retrieved 18 September 2023.