Last Round Arthurs 5: Once King & Future King
| Volume Title | Last Round Arthurs 5: Once King & Future King |
| Japanese Volume Title | ラストラウンド・アーサーズ5 過去の王と未来の王 |
| Light Novel | Last Round Arthurs: Scum Arthur and Heretic Merlin |
| Publisher | Fujimi Shobo |
| Light Novel Label | Fujimi Fantasia Bunko |
| Author | Tarou Hitsuji |
| Illustrator | Kiyotaka Haimura |
| Target Readership | Male |
| Volume | 5 |
| Release Date | January 18, 2020 |
| Pages | 360 |
| ISBN-10 | 4040734777 |
| ISBN-13 | 978-4040734774 |
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