First-seeded Ai Sugiyama was the defending champion and won in the final 6–3, 6–3 against Corina Morariu.

A champion seed is indicated in bold text while text in italics indicates the round in which that seed was eliminated. The top two seeds received a bye to the second round.

	Final
	1	Ai Sugiyama	6	6
	5	Corina Morariu	3	3

	First round							Second round							Quarterfinals							Semifinals
								1	A Sugiyama	6	6
		N Miyagi	6	3	7				S-T Wang	3	2
		L Osterloh	0	6	6										1	A Sugiyama	4	6	6
	Q	S De Beer	4	4												E deLone	6	1	1
		E deLone	6	6					E deLone	6	2	6
		N Kijimuta	1	6	1			8	Y Yoshida	3	6	2
	8	Y Yoshida	6	4	6																	1	A Sugiyama	6	6
	3	T Tanasugarn	4	7	6																	6	S-T Wang	3	2
		E-H Kim	6	5	0			3	T Tanasugarn	2	3
		M-R Jeon	4	1					L McNeil	6	6
		L McNeil	6	6												L McNeil	6	4	1
	Q	S Hisamatsu	2	2											6	S-T Wang	4	6	6
		R Hiraki	6	6					R Hiraki	3	2
	WC	S Asagoe	6	3	1			6	S-T Wang	6	6
	6	S-T Wang	3	6	6

	First round							Second round							Quarterfinals							Semifinals
	7	M Saeki	6	2
		G Helgeson-Nielsen	7	6					G Helgeson-Nielsen	3	2
	WC	S Obata	5	1					N Pratt	6	6
		N Pratt	7	6												N Pratt	2	6	2
		K Kunce	7	4	1										4	A Frazier	6	4	6
	Q	M Endo	6	6	6			Q	M Endo	0	1
	Q	Y-J Choi	4	2				4	A Frazier	6	6
	4	A Frazier	6	6																		4	A Frazier	6	6	4
	5	C Morariu	6	6																		5	C Morariu	4	7	6
		S-H Park	4	2				5	C Morariu	6	6
		M Shaughnessy	3	6	6				M Shaughnessy	3	2
		J Lee	6	2	4										5	C Morariu	7	6
		H Inoue	6	6											2	N Sawamatsu	5	3
		S Noorlander	4	1					H Inoue	6	4	6
								2	N Sawamatsu	4	6	7

• 1998 Japan Open Tennis Championships Draw