Naotsugu is tall, has short, grayish hair, bright, lively eyes and a roguish smile. Unlike Shiroe, his height in the game (183 cm or 6 feet) is approximately the same as his height in real life.
Before the Catastrophe, his character had a diagonal slice cutting through one of his eyebrows, but after Naotsugu became trapped in the game, his features changed to mirror his real face more closely, and the scar disappeared.
His original armor, while Artifact-class and serviceable even after two years of inactivity, is somewhat bland and understated. However, he acquires flashier Phantasmal-class armor developed by Akiban researchers before traveling to the Abyssal Shaft.
As the "Warrior of Panties" and an "open pervert," Naotsugu is the cheerful big brother character of Shiroe's team, albeit one subjected to frequent derision and occasional physical attacks from Akatsuki (the latter which is exaggerated in the anime). A good, solid person and the Debauchery Tea Party's most reliable tank, Naotsugu's greatest fault is his incessant need to crack off-color jokes, especially those pertaining to women's underwear, which usually results in Akatsuki kneeing him in the face. Naotsugu also believes with passion that all men are perverts, even outright claiming that all men are either open perverts like him or closet perverts and accuses Shiroe of being the latter. Oddly, he doesn't seem to apply the same standards to women.
Despite his perverted mind, Naotsugu is nevertheless a kind man who gets along well with others. This includes Akatsuki, whom he quickly becomes friends with despite her constantly kneeing him in the face and him frequently making fun of her height. While not nearly as cunning as Shiroe, he has much better interpersonal skills and can pick up on things that the latter often misses. He also has a strong sense of right and wrong, which is shown by the outright disgust he showed at PKs, saying he refuses to 'back down from freaks who attack people for fun'.
Although he constantly makes perverted jokes, Naotsugu can be surprisingly shy when on the receiving end of such humor, as he becomes flustered whenever Maryelle glomps him, hugs him, or asks him to touch her breasts, and is annoyed by Tetora's constant flirting. In addition, despite being the second-oldest member of Log Horizon (after Nyanta), Naotsugu can be rather dense and slow to catch on to things, as he still hasn't figured out that Tetora is a man in real life, something every other member of the guild knows. In spite of this, Naotsugu proves time and time again to be an invaluable member of the guild as well as a highly capable mentor to Tohya, who respects him almost as much as he does Shiroe.
One of Naotsugu's best traits is his patience and laid-back attitude, willing to roll with whatever happens. He and Shiroe became friends during one of the Tea Party's offline meetings, where he mistook Shiroe's oolong tea for pu-erh and was lectured about the difference. However, instead of getting annoyed or angry, he actively participated in the discussion, and the two became fast friends. In spite of appearances, he's pretty good at sensing his boundaries; he doesn't bother Shiroe when he sees that Shiroe's concentrating on something else, and when Shiroe rejects the warm wine Naotsugu offers to help him relax, Naotsugu doesn't bother him about it and knows that Shiroe will recover on his own.
Naotsugu is shown to greatly enjoy his new life in the world of Elder Tales; he mentions at one point that, if given a choice between staying and risking his life in an attempt to find a way back home, he would most likely choose the former, as he has no particular attachment to the real world due to not having much going for him besides the daily routine at his job.
Prior to the Catastrophe
Naotsugu was a member of the Debauchery Tea Party when he was in college, and became acquainted with Shiroe and Nyanta, among others, during this time. Apparently, among its members, he was among those with "relatively" more common sense. However, after four years (two years before the Homesteading the Noosphere expansion's release), Naotsugu took up a job as a businessman and was unable to continue playing Elder Tale.
Naotsugu lives near Tokyo with a dog. He and Shiroe have met a few times "in real life". His relationship with his family is unknown, as he mentions that while he hasn't seen his parents in the two years since he started working, he doesn't miss them much either. If he had to choose between the real world and Theldesia, he would pick Theldesia, since he claims that he has little attachment to the real world.
The Catastrophe arc
For the first time in two years, Naotsugu logged into Elder Tale to test out the new expansion pack and became one of the 30,000 Japanese players trapped inside it. After being contacted by Shiroe, and they meet at the Silverleaf Tree in Akihabara.
Saving Serara arc
Naotsugu went with Shiroe and Akatsuki to rescue Serara, a member of the Crescent Moon Alliance guild who was trapped in Susukino after the Catastrophe. He protected the team from Demiqas' guild members by using Anchor Howl, and distracted them while Nyanta and Shiroe dealt with Demiqas.
Round Table Conference arc
Ragranda Forest arc
After the success of the Round Table Conference, the formation of the Round Table Alliance, and the disbandment of Hamelin, Naotsugu and Akatsuki watched over Minori and Tohya, who are training in the field.
Naotsugu and Nyanta are among the trainers for the Summer Training Camp, led by Maryelle. They travel to the school, where they set up camp for a night. There, Naotsugu announces to the new players that the trainers would have minimal influence during training, mostly to oversee and make sure that they remain safe. Other than that, they would be on their own.
Return of the Goblin King arc
Libra Festival arc
Gold of the Kunie arc
Naotsugu travels with Shiroe and Li Gan to the north, despite not really knowing what Shiroe's intent was. However, during the other two's negotiations with Kinjo, he knew that it was doomed to fail, as his experience in business taught him that being too secretive about one's plans made it difficult for others to trust in them.
While Shiroe negotiates with William, he and Li Gan start looking for more members to the raid party when they find Tetora in a pile of snow. As she struggles to free herself, the two men comment on her hot pants and bond over their similarities. After she finally frees herself, she immediately comments on how such a fall could have been disastrous for a "cute Idol" such as herself. After being teased by Li Gan over her awkward appearance earlier, she opts to go after Naotsugu instead. After some deliberation, in the process deciding that Maryelle was the "clear winner," Naotsugu recruits her to join the Abyssal Shaft raid. When they enter Silver Sword's guild hall, Tetora was in the middle of informing the two about Demiqas' current situation and how he was happily married to a Lander woman he had abducted before he changed his ways, completely unaware that Demiqas himself was in the guild hall, having heard that Shiroe was present. Embarrassed and angered, he attacks Tetora for "running her mouth off," although Naotsugu casually blocks the kick.
By this point, Maryelle and Naotsugu have been having daily calls, after dinner at 9 p.m., something that seems innocuous to the two participants but are sure signs of a relationship to others.
Along with the rest of the Abyssal Shaft Raid Party, he wipes out against the three-way tag-team between Raid Bosses Ruseato of Seven Prison, Tarutauruga of Fourth Prison, and Ibura Habura of Third Prison. After he revives, he wakes up before Shiroe and moves him away from the Silver Sword group. Once Shiroe wakes up, he tells Naotsugu and Tetora that he has a plan to beat the raid bosses, although there was only a 15% chance of it working. Undeterred, the two respond that it was "perfect".
After a week of training, the raid party decides to take another shot at the Abyssal Shaft raid. Shiroe and Naotsugu both equip better armor for the occasion. He blocks Ruseato's first attack with Castle of Stone and later joins the raid party in the way for Ibura Habura's place, where Tetora reveal that she had entered in the Log Horizon, much to Naotsugu's dismay.
They are able to beat Ibura Habura, Tarutauruga and the Shadow Vanguard, while Shiroe successfully negotiates with Kinjo, they cleared the raid zone.
Naotsugu is still unaware of Tetora's real-life gender, nor is she interested in telling him herself. Until he figures it out on his own, she is content with teasing and harassing him. (It should be noted that the anime makes up the part where everyone else but Naotsugu and Maryelle are aware of this; as far as the light novel is concerned, either nobody else has realized Tetora's real-life gender or don't care.)
Homesteading the Noosphere arc
Naotsugu joins the Shibuya Raid Team as a member of the first party. Along with the other Tea Party members gathered at the time, he is shocked to discover that Kanami had rejoined the game and was making her way towards Yamato.
Naotsugu represents the traditional Fortress build, in contrast with Krusty's Scarlet Knight and Isaac's Juggernaut builds. Out of the three "main" Guardians, Naotsugu is also the only one to equip a shield, as the other two focus on damage rather than defense.
|Meteoros Shield (メテオロス・シールド): Powerful shield forged with ore from a radinium meteorite. Production-class item whose production requires the cooperation of someone who can summon down meteors. The backside of Naotsugu's shield is covered with stickers of panties.|
|Knight Castle Armor (騎士城の甲冑): High-power full body armor dropped from "Ruseato of the Seventh Prison." Up until the addition of the expansion pack, although it wasn't cutting-edge, it was adequate equipment for a level 90 player like Naotsugu to use.|
|Panties Notebook (ぱんつ手帳): Originally, the "Proof Notebook," this book recorded "proof" of monsters defeated. However, Naotsugu realized that it's possible to rename items in the game, so he renamed it. It has no actual in-game function.|
|Armor of Silver Oath: Made of cut demon steel material from a snow-capped mountain, the entire armor has a dull white shine. A Production-class armor with performance approaching Phantasmal-class, it increases Hate gain rate and is resistant to cold attributes. Prototype created by the collected technologies of crafters in Akiba.|
|Gaze of Lionheart: Phantasmal-class large shield with a soul of a lion that bared its fangs at god sealed within. Basic defense capability performance is high, it has the ability reduce movement speed of hostiles within a radius of several meters. According to Shiroe's memory, it should have been called "Lion's Large Shield", but for some puzzling reason the item's performance was improved.|
|Tandem Seat: Griffin saddle made for two. A product of Akiba crafters. Naotsugu's favorite even though it's not a powerful item. It makes you feel like you want to brag, but Maryelle detests it so it's fun to tease her with it.|
- Naotsugu likes reading fantasy novels, and developed some theories about the Catastrophe based on what he's seen in the books he's read.
|Debauchery Tea Party|
Aihie • Calm.H.Dale • Gingami • Gorouhachirou • Hayato • Indicus • KR • Kazuhiko • Naotsugu • Nazuna • Nurukan • Nyanta • RamMutton • Shiroe • Soujiro Seta • Stallbourne • Suikazura • Saki • Suzuna • Taigamaru • Touri • Tsukine • Whistler • Yomi • Yuko • ★Kurama☆