2023 Keio Challenger – Men's singles

Men's singles
2023 Keio Challenger
Champion	Yosuke Watanuki
Runner-up	Yuta Shimizu
Score	7–6(7–5), 6–4

Main article: 2023 Keio Challenger

Christopher O'Connell was the defending champion but chose not to defend his title.

Yosuke Watanuki won the title after defeating Yuta Shimizu 7–6^(7–5), 6–4 in the final.

Seeds

1. Yosuke Watanuki (champion)
2. Jurij Rodionov (first round)
3. Michael Mmoh (semifinals)
4. James Duckworth (second round, withdrew)
5. Maxime Cressy (withdrew)
6. Luca Nardi (quarterfinals)
7. Marc Polmans (second round)
8. Leandro Riedi (second round)

Draw

Key

• Q = Qualifier
• WC = Wild card
• LL = Lucky loser
• Alt = Alternate
• ITF = ITF entry
• PR = Protected ranking
• SR = Special ranking
• SE = Special exempt
• JE = Junior exempt
• JR = Junior Accelerator Programme entrant
• CO = College Accelerator Programme entrant
• NG = Next Gen Accelerator Program entrant
• w/o = Walkover
• r = Retired
• d = Defaulted

Finals

	Semifinals							Final
	1	Yosuke Watanuki	6	62	6
	3	Michael Mmoh	4	77	0
								1	Yosuke Watanuki	77	6
									Yuta Shimizu	65	4
		Yuta Shimizu	w/o
	Q	Yasutaka Uchiyama

Top half

	First round							Second round							Quarterfinals							Semifinals
	1	Y Watanuki	6	6
		Y-h Hsu	3	3				1	Y Watanuki	6	6
	Q	C Sinclair	3	2				LL	M Erhard	4	3
	LL	Mathys Erhard	6	6											1	Y Watanuki	3	6	6
	Q	A Holmgren	4	1											LL	G Fonio	6	2	1
	LL	G Fonio	6	6				LL	G Fonio	4	77	6
	WC	R Noguchi	2	2				8	L Riedi	6	64	4
	8	L Riedi	6	6																		1	Y Watanuki	6	62	6
	3	M Mmoh	6	6																		3	M Mmoh	4	77	0
		M Echargui	1	2				3	M Mmoh	6	5	77
		G Blancaneaux	6	61	6				G Blancaneaux	4	7	63
	Q	O Jasika	4	77	3										3	M Mmoh	78	2	6
	Q	K Ivanovski	6	5	6										6	L Nardi	66	6	4
		Z Bergs	1	7	2			Q	K Ivanovski	2	4
	LL	Y-s Chung	2	4				6	L Nardi	6	6
	6	L Nardi	6	6

Bottom half

	First round							Second round							Quarterfinals							Semifinals
	7	M Polmans	6	6
		C İlkel	1	0				7	M Polmans	4	4
		J Jung	4	5					Y Shimizu	6	6
		Y Shimizu	6	7												Y Shimizu	79	61	77
	Alt	A Çelikbilek	6	3	2											C Wong	67	77	64
		C Wong	2	6	6				C Wong	w/o
		Z Kolář	2	77	2			4	J Duckworth
	4	J Duckworth	6	64	6																		Y Shimizu	w/o
	Q	N Nakagawa	65	6	2																	Q	Y Uchiyama
		A Martin	77	1	6				A Martin	6	4	5
	WC	R Sakamoto	4	3					L Tu	2	6	7
		L Tu	6	6												L Tu	61	5
	Q	Y Uchiyama	6	6											Q	Y Uchiyama	77	7
	WC	M Imamura	1	1				Q	Y Uchiyama	2	6	6
		S-c Hong	78	78					S-c Hong	6	4	4
	2	J Rodionov	66	66

External links

• Main draw
• Qualifying draw