Released on July 23, 1998 (Thursday) in Japan.

This game is known in Japan as "The King of Fighters '98 - Dream Match Never Ends".

It is said that this game is a 'dream match' for more reasons than one - this KOF is said to exist only in Shingo's dream - each character in this dream match was Shingo's impression of these characters, based on either personal experience or his notes in his notebook.

Yuri has a long record of taking movements from other characters, especially Capcom (see previous KOF entries). In this new opus : Yuri's new special attack 'Shin! Chou Upper' is a knock off of Ryu's Shin Shoryuu Ken. She also has a movement similar to Terry's burn knuckle. Finally, her Forward+A is a parody of Sakura's Flower Kick.

KOF98 contains pieces of music from older KOFs.
For example, the character select music when a second player joins in is straight from KOF 96 (it's called Roulette).
Here's a complete list of themes, the teams (or individuals) they belong to and the games they were taken from :
Esaka? (Japan Team) : KOF 96 (Japan Team's theme music).
Esaka (95-style Kyo Kusanagi) : KOF 94 (Japan Team's theme music).
Kurikinton (Fatal Fury Team) : Fatal Fury 2 (Terry Bogard's theme music).
Art of Fight (Art of Fighting Team) : Art of Fighting (Ryo Sakazaki's and Ryuhaku Todo's theme music).
Rumbling in the City (Ikari Team) : KOF 96 (Ikari Team's theme music).
Shin! Senritsu no Dora (Psycho Soldier Team) : KOF95 (Psycho Soldier Team's theme music).
Fairy (Gals Fighters Team) : KOF 96 (Chizuru Kagura's theme music).
Seoul Town (Korea Team) : Real Bout Fatal Fury (Kim Kaphwan's theme music).
Bloody (New Face Team) : KOF 97 (New Face Team's theme music).
Rhythmic Hallucination (Orochi Yashiro) : KOF 97 (Orochi New Face Team's theme music).
C62 (Ryuji Yamazaki) : Real Bout Fatal Fury Special (Ryuji Yamazaki's theme music).
Blue Mary's Blues (Blue Mary) : Real Bout Fatal Fury Special (Blue Mary's theme music).
London March (Billy Kane) : Real Bout Fatal Fury Special (Billy Kane's theme music).
Arashi no Saxophone (Iori Yagami) : KOF 95 (Revenge Team's theme music).
Arashi no Saxophone 2 (Mature, Vice) : KOF 96 (Iori Team's theme music).
Slum No. 5 (USA Sports Team) : KOF 94 (USA Sports Team's theme music).
Still Green (Shingo Yabuki) : KOF 97 (Shingo Yabuki's theme music).
Ketchaku R&D (Omega Rugal) : first half from KOF 94 (Rugal Bernstein's theme music), second half from KOF 95 (Omega Rugal's theme music).
Ne! ('94 Gals Fighters Team) : KOF 94 (Gals Fighters Team's theme music).

Also to note that the music that is played prior to facing Rugal (Kettou R&D) is also from KOF 94 (as the theme for Rugal's first form).

When Choi Bounge appears, a 7 seconds sample from a song is played. This song is 'Choi Bounge Ondo', which appeared in the KOF 97 Arrange SoundTracks. The song became quite popular in Japan.

Mr. Big from Art of Fighting makes a small cameo appearance in the USA Wharf background, during the first rounds.

About Kyo Version 95:
Because the introduction of different versions for this character included as "hidden features" in KOF '97 was such a hit with fans, designers thought, another version of Kyo in KOF '98 would make the game more inviting. Designers also remember that both versions for Kyo Kusanagi for game tests were equally popular. This concept for different versions of this character subsequently became the basis for the 'Kyo clones'.

In the Japan Street stage, during the second round if you look in the middle of the background where some shops are, you can see tiny moving people who look like Iori, Mai and Terry Bogard. In the third and fifth round, you can see two people doing hand signals, they look similar to Kyo Kusanagi & Shingo Yabuki. In the fourth round, you can see Mai and Terry.

A serious bug:
Using a USA bios rom if you insert a coin on the 'winners don't use drugs' screen on a single slot the games will use the neo+geo bios s1 tile-set rather than the game tiles, this causes most of the graphics to be hidden and the games to be unplayable, it will also end up using the main-board z80 bios so sound will be broken, the games should fix themselves if you let them run another attact loop after game over, on a multi-slot the games will reset. This is one of the first 4 'gigapower' games, the bug was fixed after that.

Leona, Ralph and Clark are playable characters in the Foma 90x Series Mobile Phones game 'Metal Slug Survivors'.

Soundtrack releases:
[JP] Aug. 19, 1998; The King of Fighters '98 - Dream Match Never Ends [PCCB-00334] - Pony Canyon.
[JP] Sep. 18, 1998; The King of Fighters '98 - Dream Match Never Ends Arrange Sound Trax [PCCB-00337] - Pony Canyon.
(JP] Oct. 07, 1998; The King of Fighters '98 - Dream Match Never Ends Drama CD [PCCB-00339] - Pony Canyon.