| NEC PC-9801 Series 5.25in. disk |  Kaijuu Daisensou T.D.F. - Kesshi no Genshirou Bouei Sakusen | 1988 | Data West, Inc. Japan |
| NEC PC-9801 Series 5.25in. disk | Kaiketsu Nikki | 1994 | Ange Japan |
| NEC PC-9801 Series 5.25in. disk | Kairaku no Okite - Aoi Taiken 18 | 1994 | Moonchild Soft. |
| NEC PC-9801 Series 5.25in. disk | Kaki Taoshi - Spell Master | 199? | Nichikon Japan |
| NEC PC-9801 Series 5.25in. disk | Kakinoki Shougi | 1994 | ASCII Corp. Japan |
| NEC PC-9801 Series 5.25in. disk | Kakutou Musume Ryoko 18 | 1993 | Musumeya |
| NEC PC-9801 Series 5.25in. disk | Kaleidoscope - Scenario Set Dai 2 Dan, Hakkan Wakusei Model NFHB21008 | 198? | Hot-B Japan |
| NEC PC-9801 Series 5.25in. disk |  Kaleidoscope - Scenario Set Dai 2 Dan, Hakkan Wakusei Model NFHB24005 | 198? | Hot-B Japan |
| NEC PC-9801 Series 5.25in. disk | Kami no Machi | 1989 | Panther Soft. Japan |
| NEC PC-9801 Series 5.25in. disk | Kamigami no Daichi - Kojiki Gaiden Model KN10451010 | 1993 | KOEI Co., Ltd. Japan |
| NEC PC-9801 Series 5.25in. disk | Kanako 18 | 1996 | IDES Japan |
| NEC PC-9801 Series 5.25in. disk | Kangoku Country Club | 1996 | Dollhouse Japan |
| NEC PC-9801 Series 5.25in. disk | Kankin | 1995 | Illusion Core Japan |
| NEC PC-9801 Series 5.25in. disk | Kao Floppy Gekijou - Route 246 Satsujin Annai | 1991 | Fairytale Japan |
| NEC PC-9801 Series 5.25in. disk | Kaou Derby | 1992 | Progress Japan |
| NEC PC-9801 Series 5.25in. disk | Karateka 2DD Ver. P | 1988 | Broderbund Japan |
| NEC PC-9801 Series 5.25in. disk | Karateka 2HD Ver. P | 1988 | Broderbund Japan |
| NEC PC-9801 Series 5.25in. disk | Kareinaru Jinsei - Minasan no Okage Desu. 18 | 1991 | Fairytale Japan |
| NEC PC-9801 Series 5.25in. disk | Kawaisou Monogatari | 1988 | SystemSoft Corp. Japan |
| NEC PC-9801 Series 5.25in. disk | Kawanakajima Ibunroku | 1992 | KSK Kure Soft. Koubou Japan |
| NEC PC-9801 Series 5.25in. disk | Kawarazaki-ke no Ichizoku 18 | 1992 | Silky's Japan |
| NEC PC-9801 Series 5.25in. disk | Kax III | 1993 | Micro Cabin Co. Japan |
| NEC PC-9801 Series 5.25in. disk | KDD CG 1 | 199? | Unknown Japan |
| NEC PC-9801 Series 5.25in. disk | KDD CG 2 | 199? | Unknown Japan |
| NEC PC-9801 Series 5.25in. disk | Keichu | 199? | Unknown Japan |
| NEC PC-9801 Series 5.25in. disk | Kekkou Kamen - Oshioki Paradise no Maki | 1994 | Dynamic Production |
| NEC PC-9801 Series 5.25in. disk | Kemesis | 199? | Unknown Japan |
| NEC PC-9801 Series 5.25in. disk | Kerakera Hoshi | 1992 | Cocktail Soft. Japan |
| NEC PC-9801 Series 5.25in. disk | Ketsuekigata-boshi Uranai | 199? | Kogaku System |
| NEC PC-9801 Series 5.25in. disk | Ki - Aku no RPG | 1991 | Soft Plan Co., Ltd. Japan |
| NEC PC-9801 Series 5.25in. disk | Kibun wa Pastel Touch | 1989 | Great Japan |
| NEC PC-9801 Series 5.25in. disk | Kids - SAP 2nd. File | 1991 | Great Japan |
| NEC PC-9801 Series 5.25in. disk | Kigen - Kagayaki no Hasha | 1991 | Riverhill Soft. Japan |
| NEC PC-9801 Series 5.25in. disk | Kikou Shidan - Panzer Division | 1990 | Artdink Corp. Japan |
| NEC PC-9801 Series 5.25in. disk | Kikou Shidan II - Panzer Division | 1992 | Artdink Corp. Japan |
| NEC PC-9801 Series 5.25in. disk | Kikou Soushin Val-Kaizer | 1992 | Silence Japan |
| NEC PC-9801 Series 5.25in. disk | Kimagure Orange Road - Natsu no Mirage Model 84154 | 1988 | Micro Cabin Co. Japan |
| NEC PC-9801 Series 5.25in. disk | Kimagure Orange Road - Natsu no Mirage Model 84155 | 1988 | Micro Cabin Co. Japan |
| NEC PC-9801 Series 5.25in. disk | Kimi Dake ni Ai wo... 18 | 1991 | Game Technopolis Japan |
| NEC PC-9801 Series 5.25in. disk | Kinbaku no Yakata | 1995 | XYZ Japan |
