# 2024 Keio Challenger – Men's singles

Yosuke Watanuki was the defending champion but chose not to defend his title.
Yuta Shimizu won the title after defeating Li Tu 6–7$^{(4–7)}$, 6–4, 6–2 in the final.

## Seeds

* Mattia Bellucci (first round)
* Yasutaka Uchiyama (first round)
* Coleman Wong (quarterfinals)
* Alex Bolt (first round)
* Sho Shimabukuro (first round)
* Li Tu (final)
* Jurij Rodionov (first round)
* Constant Lestienne (semifinals)

## Draw
### Key

* Q = Qualifier
* WC = Wild card
* LL = Lucky loser
* Alt = Alternate
* SE = Special exempt
* PR = Protected ranking
* ITF = ITF entry
* JE = Junior exempt
* w/o = Walkover
* r = Retired
* d = Defaulted
* SR = Special ranking

### Finals

| Semifinals | Semifinals | Semifinals | Semifinals | Semifinals | Final | Final | Final | Final | Final |
| 8 | Constant Lestienne | 2 | 6 | 6$^3$ | | | | | |
| 6 | Li Tu | 6 | 3 | 7$^7$ | | | | | |
| 6 | Li Tu | 6 | 3 | 7$^7$ | 6 | Li Tu | 7$^7$ | 4 | 2 |
| | | | | | | Yuta Shimizu | 6$^4$ | 6 | 6 |
| | Yuta Shimizu | 6 | 6 | | | Yuta Shimizu | 6$^4$ | 6 | 6 |
| | Benjamin Hassan | 2 | 3 | | | | | | |

### Top half

| First round | First round | First round | First round | First round | Second round | Second round | Second round | Second round | Second round | Quarterfinals | Quarterfinals | Quarterfinals | Quarterfinals | Semifinals | Semifinals | Semifinals | Semifinals | Semifinals |
| 1 | M Bellucci | 6 | 4 | 3 | | | | | | | | | | | | | | |
| | T-l Wu | 4 | 6 | 6 | | T-l Wu | 7$^9$ | 2 | 6$^6$ | | | | | | | | | |
| | A Zakharov | 6 | 6 | | | A Zakharov | 6$^7$ | 6 | 7$^8$ | | | | | | | | | |
| | R Noguchi | 4 | 4 | | | | | | | | A Zakharov | 4 | 2 | | | | | |
| | M Dodig | 4 | 6 | 4 | | | | | | 8 | C Lestienne | 6 | 6 | | | | | |
| | N Basilashvili | 6 | 2 | 6 | | N Basilashvili | 3 | 2$^r$ | | | | | | | | | | |
| Q | C Negritu | 6 | 5 | 4 | 8 | C Lestienne | 6 | 4 | | | | | | | | | | |
| 8 | C Lestienne | 3 | 7 | 6 | | | | | | | | | | 8 | C Lestienne | 2 | 6 | 6$^3$ |
| 3 | C Wong | 6 | 6 | | | | | | | | | | | 6 | L Tu | 6 | 3 | 7$^7$ |
| WC | Lennon Roark Jones | 2 | 1 | | 3 | C Wong | 7$^7$ | 6 | | | | | | | | | | |
| Q | J-s Nam | 2 | 2 | | | S Mochizuki | 6$^2$ | 3 | | | | | | | | | | |
| | S Mochizuki | 6 | 6 | | | | | | | 3 | C Wong | 0 | 4 | | | | | |
| | A Blockx | 1$^r$ | | | | | | | | 6 | L Tu | 6 | 6 | | | | | |
| Q | P Sekulic | 5 | | | Q | P Sekulic | 6$^5$ | 3 | | | | | | | | | | |
| | Y Demin | 1 | 0$^r$ | | 6 | L Tu | 7$^7$ | 6 | | | | | | | | | | |
| 6 | L Tu | 6 | 3 | | | | | | | | | | | | | | | |

### Bottom half

| First round | First round | First round | First round | First round | Second round | Second round | Second round | Second round | Second round | Quarterfinals | Quarterfinals | Quarterfinals | Quarterfinals | Quarterfinals | Semifinals | Semifinals | Semifinals |
| 7 | J Rodionov | 2 | 4 | | | | | | | | | | | | | | |
| WC | R Sakamoto | 6 | 6 | | WC | R Sakamoto | 7 | 6 | | | | | | | | | |
| Q | F Cinà | 6 | 3 | 6 | Q | F Cinà | 5 | 4 | | | | | | | | | |
| | G den Ouden | 4 | 6 | 4 | | | | | | WC | R Sakamoto | 3 | 7$^7$ | 6$^3$ | | | |
| WC | M Imamura | 6 | 4 | 6 | | | | | | | Y Shimizu | 6 | 6$^4$ | 7$^7$ | | | |
| | D Sweeny | 3 | 6 | 3 | WC | M Imamura | 4 | 6$^4$ | | | | | | | | | |
| | Y Shimizu | 7$^8$ | 6 | | | Y Shimizu | 6 | 7$^7$ | | | | | | | | | |
| 4 | A Bolt | 6$^6$ | 1 | | | | | | | | | | | | Y Shimizu | 6 | 6 |
| 5 | S Shimabukuro | 1 | 4 | | | | | | | | | | | | B Hassan | 2 | 3 |
| | B Hassan | 6 | 6 | | | B Hassan | 6 | 6 | | | | | | | | | |
| | D Svrčina | 6 | 6 | | | D Svrčina | 4 | 1 | | | | | | | | | |
| Q | J Paul | 3 | 4 | | | | | | | | B Hassan | 7$^7$ | 6$^8$ | 6 | | | |
| Q | O Jasika | 3 | 7 | 4 | | | | | | | J McCabe | 6$^1$ | 7$^{10}$ | 2 | | | |
| | J McCabe | 6 | 5 | 6 | | J McCabe | 5 | 6 | 6 | | | | | | | | |
| | E Ymer | 7$^7$ | 2 | 7$^7$ | | E Ymer | 7 | 3 | 3 | | | | | | | | |
| 2 | Y Uchiyama | 6$^1$ | 6 | 6$^5$ | | | | | | | | | | | | | |