Rira Kosaka
2025
| J100 ALMATY-2 | [2] | Quarter |
| J100 ALMATY | [3] | Semi |
| J30 SHYMKENT | [1] | Win |
| J60 MAHDIA | [2] | Quarter |
| J100 TUNIS | Win | |
| J100 SOUSSE | Win | |
| J300 NONTHABURI | 1R | |
| J200 NONTHABURI | 2R | |
| J200 KOLKATA | 2R | |
| J200 CHANDIGARH | 1R | |
| J300 NEWDELHI | 1R |
2024
| J100 HONGKONG | 1R | |
| J60 CHANGHUA-2 | [3] | Final |
| J60 CHANGHUA | [4] | 2R |
| J300 WANJU | 3R | |
| J100 KAWAGUCHI | 1R | |
| J500 OSAKA | 1R | |
| J200 SYDNEY | 2R | |
| J30 YAMANASHI | [1] | Quarter |
| J60 MIKICITY | [2] | Semi |
| J100 PLANTATION | [8] | 3R |
| J100 CORALGABLES,FL | [12] | 3R |
| J100 DELRAYBEACH | [11] | 1R |
| J60 BAYAMON | [4] | Win |
| J30 BAYAMON | [1] | Win |
2023
| J30 MATSUYAMA | [5] | Semi |
| J30 GIFU | [5] | 2R |
| J200 NAGOYA | 1R | |
| J60 MIKICITY-2 | [2] | Semi |
| J60 MIKICITY | [4] | Final |
2022
| J5 MATSUYAMA | [3] | 2R |
| J5 GIFU | [1] | Final |
| J3 ANDONG | 1R | |
| JB1 OSAN-ASIACLOSED | 3R | |
| J2 CHUNCHEON | 1R | |
| JAOSAKA | 1R | |
| J4 MIKICITY-2 | 1R | |
| J4 MIKICITY | Final | |
| J4 EINDHOVEN | 2R | |
| J4 HILLEGOM | 2R | |
| J4 NONTHABURI-2 | Quarter | |
| J4 NONTHABURI | Semi | |
| J5 KURUME | 2R |
Nation
JPN
Generation
Born in 2008 (16-17 years old)
World Ranking
Junior World Ranking　201th
Year-end Junior World Ranking
- Year-end 2024 347th
- Year-end 2023 920th
- Year-end 2022 512th
- Year-end 2021 2183th
Match Details
2025 J100 ALMATY-2
| W | 2R | Sofia Vasiltsova | 5-7 6-1 6-4 |
| W | 3R | Aleksandra Khomitskaya | 6-3 7-6 |
| L | QF | Ha Eum Lee | 6-7 1-6 |
2025 J100 ALMATY
| W | 2R | Lu Mengqiao | 6-4 7-5 |
| W | 3R | Eva Korysheva | 6-4 6-4 |
| W | QF | Satima Toregen | 6-1 6-4 |
| L | SF | Alena Kharchenko | 5-7 0-6 |
2025 J30 SHYMKENT
| W | 2R | Lyaissan Nurusheva | 6-2 6-2 |
| W | 3R | Violetta Volkova | 6-1 6-0 |
| W | QF | Seohyeon Kim | 7-5 6-3 |
| W | SF | Sara Khamitova | 6-3 6-2 |
| W | F | Yasmin Dyussembayeva | 7-5 6-1 |
2025 J60 MAHDIA
| W | 1R | Emna Mathlouthi | 6-2 6-0 |
| W | 2R | Yosr Stambouli | 5-7 6-3 6-1 |
| L | QF | Sarra Attig | 1-6 6-4 3-6 |
2025 J100 TUNIS
| W | 1R | Vega Aguilar Ferrandez | 6-0 6-4 |
| W | 2R | Sasha Natalie Chimedza | 7-5 6-2 |
| W | QF | Eva Kaliadina | 6-1 6-2 |
| W | SF | Ellen Hirschi | 6-2 6-1 |
| W | F | Anna Kartseva | - - - |
2025 J100 SOUSSE
| W | 1R | Rined Saafi | 7-5 6-1 |
| W | 2R | Anna Kartseva | 7-6 6-3 |
| W | QF | Angelica Sara | 6-2 4-6 6-4 |
| W | SF | Ellen Hirschi | 6-4 7-5 |
| W | F | Eva Kaliadina | 6-1 3-6 6-3 |
2025 J300 NONTHABURI
| L | 1R | Alisa Terentyeva | 1-6 1-6 |
2025 J200 NONTHABURI
| W | 1R | Lidia Podgorichani | 1-6 6-2 7-6 |
| L | 2R | Maayan Laron | 5-7 4-6 |
2025 J200 KOLKATA
| W | 1R | Albina Kakenova | 6-1 6-4 |
| L | 2R | Yesung Choo | 6-7 0-6 |
2025 J200 CHANDIGARH
| L | 1R | Manon Favier | 2-6 3-6 |
2025 J300 NEWDELHI
| L | 1R | Manon Favier | 6-7 2-6 |
2024 J100 HONGKONG
| L | 1R | Anastasia Efremova | 6-3 3-6 4-6 |
2024 J60 CHANGHUA-2
| W | 1R | Yan Rong Tzeng | 5-7 6-2 6-2 |
| W | 2R | Min Jen Huang | 6-2 7-6 |
| W | QF | Yi-Ching Huang | 6-3 6-3 |
| W | SF | Yeseo Park | 6-7 6-4 7-6 |
| L | F | Tennielle Madis | 0-6 4-6 |
2024 J60 CHANGHUA
| W | 1R | Siang-Ling Yang | 6-4 6-4 |
| L | 2R | Yu-Ching Wang | 7-5 3-6 6-7 |
2024 J300 WANJU
| W | 1R | Malaylack Delilah Pathummakuronen | 6-7 6-3 6-1 |
| W | 2R | Yu-Chen Lin | 6-4 6-7 6-3 |
| L | 3R | Kanon Sawashiro | 6-2 5-7 4-6 |
2024 J100 KAWAGUCHI
| L | 1R | Gabrielle Villegas | 2-6 6-4 3-6 |
2024 J500 OSAKA
| L | 1R | Lea Nilsson | 2-6 2-6 |
2024 J200 SYDNEY
| W | 1R | Brooke Komorowski | 6-3 6-2 |
| L | 2R | Renee Alame | 2-6 3-6 |
2024 J30 YAMANASHI
| W | 1R | Risa Ookoshi | 4-6 6-3 7-6 |
| W | 2R | Natsuki Yamagami | 6-4 6-2 |
| L | QF | Mina Kono | 3-6 6-4 9-11 |
2024 J60 MIKICITY
| W | 1R | Yuki Nishikawa | 6-1 6-3 |
| W | 2R | Natsuki Yamagami | 6-4 4-6 7-6 |
| W | QF | Yuka Naito | 6-4 4-6 7-5 |
| L | SF | Amina Salibayeva | 6-7 4-6 |
2024 J100 PLANTATION
| W | 1R | Sarah Ye | 6-4 6-4 |
| W | 2R | Katerina Shabashkevich | 6-0 6-1 |
| L | 3R | Vessa Turley | 2-6 4-6 |
2024 J100 CORALGABLES,FL
| W | 1R | Sydney Barnhart | 6-3 6-4 |
| W | 2R | Thea Latak | 7-6 6-1 |
| L | 3R | Sara Shumate | 6-1 4-6 3-6 |
2024 J100 DELRAYBEACH
| L | 1R | Zaire Clarke | 2-6 3-6 |
2024 J60 BAYAMON
| W | 2R | Lila Bodur | 6-0 6-1 |
| W | 3R | Addison Iacono | 6-0 6-3 |
| W | QF | Sarah Ye | 6-7 6-2 6-4 |
| W | SF | Nicole Okhtenberg | 6-3 6-4 |
| W | F | Kaia Giribalan | 6-4 6-3 |
2024 J30 BAYAMON
| W | 2R | Arina Vansovich | 6-3 6-2 |
| W | 3R | Simran Makker | 6-3 6-0 |
| W | QF | Kaya Baker | 6-1 6-2 |
| W | SF | Karolina Lincer | 7-5 6-2 |
| W | F | Addison Iacono | 6-2 6-2 |
2023 J30 MATSUYAMA
| W | 1R | Miyu Sakai | 6-4 6-1 |
| W | 2R | Chiharu Abe | 6-3 6-0 |
| W | QF | Ayane Takagi | 6-2 6-0 |
| L | SF | Risa Ueno | 4-6 1-6 |
2023 J30 GIFU
| W | 1R | Naomi Hagi | 6-3 6-0 |
| L | 2R | Yui Komada | 1-6 4-6 |
2023 J200 NAGOYA
| L | 1R | Ran Inaba | 5-7 0-6 |
2023 J60 MIKICITY-2
| W | 1R | Cocomi Saito | 3-6 6-1 6-3 |
| W | 2R | Yui Komada | 6-3 6-3 |
| W | QF | Yuki Morishita | 7-6 6-1 |
| L | SF | Risa Ueno | 4-6 3-6 |
2023 J60 MIKICITY
| W | 1R | Rio Otaki | 4-6 6-1 6-1 |
| W | 2R | Yui Ueda | 6-3 6-3 |
| W | QF | Uta Asakura | 6-2 6-4 |
| W | SF | Hinata Furutani | 6-4 6-1 |
| L | F | Kanon Sawashiro | 2-6 2-6 |
2022 J5 MATSUYAMA
| W | 1R | Natsuki Yamagami | 7-6 6-2 |
| L | 2R | Kurea Hayasaka | 2-6 3-6 |
2022 J5 GIFU
| W | 1R | Konatsu Fujii | 6-2 7-5 |
| W | 2R | Seina Kishimoto | 6-2 6-3 |
| W | QF | Ran Inaba | 6-4 6-7 6-3 |
| W | SF | Himari Hayashi | 3-6 7-5 6-4 |
| L | F | Azuna Ichioka | 3-6 6-2 4-6 |
2022 J3 ANDONG
| L | 1R | Ha Eum Lee | 4-6 6-7 |
2022 JB1 OSAN-ASIACLOSED
| W | 1R | Ha Yoon Son | 7-5 6-2 |
| W | 2R | Jaeah Lee | 4-6 6-0 6-3 |
| L | 3R | Onyu Choi | 2-6 4-6 |
2022 J2 CHUNCHEON
| L | 1R | Nahyeong Cho | 1-6 2-6 |
2022 JAOSAKA
| L | 1R | Naomi Xu | 0-6 2-6 |
2022 J4 MIKICITY-2
| L | 1R | Suzuna Oigawa | 2-6 2-6 |
2022 J4 MIKICITY
| W | 1R | Yuna Kadowaki | 3-6 6-0 6-3 |
| W | 2R | Himari Hayashi | 6-1 6-1 |
| W | QF | Yu Kikawa | 6-3 7-6 |
| W | SF | Mona Narita | - - - |
| L | F | Aely Arai | 4-6 4-6 |
2022 J4 EINDHOVEN
| W | 1R | Ava Williamson | 7-6 2-6 4-3 |
| L | 2R | Annelin Bakker | 1-6 3-6 |
2022 J4 HILLEGOM
| W | 1R | Emily Schut | 6-3 7-5 |
| L | 2R | Indira Lepage | 6-4 0-6 3-6 |
2022 J4 NONTHABURI-2
| W | 1R | Maria Mauad De Souza | 6-1 7-5 |
| W | 2R | Pimmada Thongkum | 6-3 7-6 |
| W | 3R | Viera Deeperm | 6-1 6-3 |
| L | QF | Yuno Kitahara | 0-6 5-7 |
2022 J4 NONTHABURI
| W | 1R | Chulapat Sathutham | 6-1 6-1 |
| W | 2R | Sin Yu Che | 6-1 6-4 |
| W | 3R | Hyunyee Lee | 2-6 7-5 6-3 |
| W | QF | Kaho Oyama | 6-3 6-4 |
| L | SF | Jiayou Li | 1-6 1-6 |
2022 J5 KURUME
| W | 1R | Yu Kikawa | 1-6 6-4 6-2 |
| L | 2R | Kurumi Tamura | 1-6 4-6 |
Junior Tennis Database is a site that summarizes the results of ITF junior tennis tournaments.
Number of registered tournaments: 9586, Number of registered players: 5,950, Number of registered results: 317,489