2017 Keio Challenger

The 2017 Keio Challenger was a professional tennis tournament played on hard courts. It was the twelfth (ATP) and first (ITF) editions of the tournament and part of the 2017 ATP Challenger Tour and the 2017 ITF Women's Circuit. The tournament offered $50,000+H in prize money for the men and $25,000 prize money for the women. It took place in Yokohama, Japan between 27 February and 5 March 2017 for the men's edition and between 6 and 12 March 2017 for the women's.

Seeds

 * 1 Rankings are as of February 20, 2017.

Other entrants
The following players received wildcards into the singles main draw:
 * 🇯🇵 Sora Fukuda
 * 🇯🇵 Masato Shiga
 * 🇯🇵 Kaito Uesugi
 * 🇯🇵 Yosuke Watanuki

The following player received entry into the singles main using a protected ranking:
 * 🇩🇪 Cedrik-Marcel Stebe

The following player received entry into the singles main draw as a special exemption:
 * Lloyd Harris

The following players received entry from the qualifying draw:
 * 🇬🇧 Brydan Klein
 * 🇰🇷 Kwon Soon-woo
 * 🇦🇺 Blake Mott
 * 🇯🇵 Takuto Niki

Seeds

 * 1 Rankings are as of February 27, 2017.

Other entrants
The following players received wildcards into the singles main draw:
 * 🇯🇵 Sumina Eshiro
 * 🇯🇵 Hayaka Murase
 * 🇯🇵 Megumi Nishimoto
 * 🇯🇵 Suzuho Oshino

The following players received entry from the qualifying draw:
 * 🇯🇵 Haruna Arakawa
 * 🇯🇵 Erina Hayashi
 * 🇯🇵 Miyabi Inoue
 * 🇯🇵 Haruka Kaji
 * 🇯🇵 Rio Kitagawa
 * 🇯🇵 Mai Minokoshi
 * 🇯🇵 Ramu Ueda
 * 🇯🇵 Aki Yamasoto

Men's singles

 * 🇯🇵 Yūichi Sugita def. 🇰🇷 Kwon Soon-woo 6–4, 2–6, 7–6(7–2).

Women's singles

 * 🇯🇵 Akiko Omae def. 🇯🇵 Mayo Hibi 7–5, 6–2.

Men's doubles

 * Marin Draganja / Tomislav Draganja def. 🇧🇪 Joris De Loore / 🇦🇺 Luke Saville 4–6, 6–3, [10–4].

Women's doubles

 * 🇯🇵 Ayaka Okuno / 🇯🇵 Erika Sema def. 🇯🇵 Kanako Morisaki / 🇯🇵 Minori Yonehara, 6–4, 6–4.