2018 Keio Challenger – Men's doubles

Marin and Tomislav Draganja were the defending champions but chose not to defend their title.

Men's doubles
2018 Keio Challenger
Champions	Tobias Kamke Tim Pütz
Runners-up	Sanchai Ratiwatana Sonchat Ratiwatana
Score	3–6, 7–5, [12–10]

Main article: 2018 Keio Challenger

Tobias Kamke and Tim Pütz won the title after defeating Sanchai and Sonchat Ratiwatana 3–6, 7–5, [12–10] in the final.

Seeds

1. Sanchai Ratiwatana / Sonchat Ratiwatana (final)
2. Sriram Balaji / Yasutaka Uchiyama (first round)
3. Peng Hsien-yin / Andreas Siljeström (quarterfinals)
4. Toshihide Matsui / Yi Chu-huan (quarterfinals)

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

	First round							Quarterfinals							Semifinals							Final
	1	Sa Ratiwatana So Ratiwatana	6	6
	WC	S Hazawa M Imamura	3	4				1	Sa Ratiwatana So Ratiwatana	6	7
		Z Li S Robert	6	4	[0]				M Purcell A Whittington	3	5
		M Purcell A Whittington	3	6	[10]										1	Sa Ratiwatana So Ratiwatana	5	6	[10]
	4	T Matsui C-h Yi	6	2											WC	T Ito K Uesugi	7	2	[6]
	Q	M Donati E Leshem	1	1r				4	T Matsui C-h Yi	79	5	[8]
	WC	T Ito K Uesugi	6	6				WC	T Ito K Uesugi	67	7	[10]
	WC	Masahiro Fukuda Eiji Yamasaki	2	3																		1	Sa Ratiwatana So Ratiwatana	6	5	[10]
		T Altuna H Hurkacz	4	2																			T Kamke T Pütz	3	7	[12]
		C Rungkat Ze Zhang	6	6					C Rungkat Ze Zhang	6	6
		B Klein L Margaroli	77	65	[6]			3	H-y Peng A Siljeström	2	2
	3	H-y Peng A Siljeström	62	77	[10]											C Rungkat Ze Zhang	3	3
		M Gong C-p Hsieh	6	77												T Kamke T Pütz	6	6
		T Chen J Jung	3	65					M Gong C-p Hsieh	61	63
		T Kamke T Pütz	6	6					T Kamke T Pütz	77	77
	2	S Balaji Y Uchiyama	4	3

References

• Main draw
• Qualifying draw