Men's doubles
2018 Keio Challenger
Final
Champions	Tobias Kamke Tim Pütz
Runners-up	Sanchai Ratiwatana Sonchat Ratiwatana
Score	3–6, 7–5, [12–10]
Events
Singles men women Doubles men women
← 2017 · Keio Challenger · 2019 →

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

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

	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

• Main draw
• Qualifying draw