| Rank | Name | IPv4 addresses | IPv6 /64 networks | AS numbers | Prefixes |
|---|---|---|---|---|---|
| SoftBank Corp. | 53,914,112 | 1.06 x 244 | 3 | 693 | |
| NTT Communications Corporation | 28,817,152 | 242 | 8 | 228 | |
| KDDI CORPORATION | 18,154,496 | 1.25 x 241 | 1 | 524 | |
| 4 | JCOM Co., Ltd. | 14,266,368 | 1.25 x 236 | 11 | 683 |
| 5 | Research Organization of Information and Systems, National Institute of Informa | 9,160,771 | 233 | 1 | 605 |
| 6 | ARTERIA Networks Corporation | 7,004,928 | 1.56 x 236 | 3 | 242 |
| 7 | Internet Initiative Japan Inc. | 3,863,040 | 1.03 x 234 | 1 | 181 |
| 8 | Sony Network Communications Inc. | 3,851,264 | 1.03 x 237 | 1 | 75 |
| 9 | BIGLOBE Inc. | 3,670,528 | 1.13 x 235 | 1 | 36 |
| 10 | OPTAGE Inc. | 3,067,904 | 232 | 2 | 70 |
| 11 | NTT DOCOMO, INC. | 2,652,672 | 1.3 x 233 | 1 | 1,218 |
| 12 | NTT PC Communications, Inc. | 2,617,344 | 1.56 x 233 | 1 | 455 |
| 13 | FreeBit Co.,Ltd. | 2,047,232 | 233 | 1 | 428 |
| 14 | FUJITSU LIMITED | 1,833,984 | 232 | 2 | 157 |
| 15 | TOKAI Communications Corporation | 1,644,288 | 1.31 x 235 | 1 | 197 |
| 16 | NTT-ME Corporation | 1,628,416 | 242 | 1 | 50 |
| 17 | IDC Frontier Inc. | 1,439,232 | 234 | 1 | 177 |
| 18 | Chubu Telecommunications Company, Inc. | 1,385,984 | 233 | 83 | 14 |
| 19 | Asahi Net | 1,277,952 | 1.13 x 235 | 1 | 64 |
| 20 | SAKURA Internet Inc. | 1,015,552 | 1.13 x 236 | 4 | 117 |