Naotsugu

"Gone straight to acting like animals ‘cos you miss your mama? A surprise attack isn’t enough to warrant a victory party, guys."

- Naotsugu, volume 1, chapter 3

Naotsugu is Shiroe's friend and another player trapped in Elder Tale. He is a Human Guardian-Border Patrol and an important part of Shiroe's team along with Akatsuki.

In the real world, his name is Naotsugu Hasegawa (葉瀬川直継), and he is 25 years old. He was a member of the Abyssal Shaft Raid Party and of the Shibuya Raid Team.

Appearance
Naotsugu is tall, has short, grayish hair, bright, lively eyes and a roguish smile. Unlike Shiroe, his height in the game (183cm 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.

Personality
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. However, he becomes flustered whenever Maryelle glomps him, hugs him, or asks him to touch her breasts.

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.

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.

Gold of the Kunie arc
Naotsugu travels with Shiroe and ReGan 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 ReGan start looking for more members to the raid party when they find Tetora into 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 ReGan 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.

Equipment
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.

Trivia

 * Naotsugu likes reading fantasy novels, and developed some theories about the Catastrophe based on what he's seen in the books he's read.