Roe2 is Shiroe's alternate character avatar, a Half-Alv Summoner-Vampanella. Although she was originally on Mare Tranquillitatis, her body ends up being used by a Fool who is intent on finding out who was rightfully in possession of Theldesia's Empathiom, whereas the Genius are simply intent on harvesting it by killing Earthlings and Adventurers alike. As a result, Roe2 primarily opposes the Genius and aids her "big brother's" (Shiroe's) cause.
Roe2 has the appearance of a tall woman dressed in a white coat wearing glasses, with rather voluptuous curves - the latter made KR and RamMutton dub her "Ero-ko". Notably, she dons the same cloak as Shiroe and bears a striking resemblance to him. In spite of that, few people have figured out that she was actually Shiroe's alt.
Roe2 is naive about Adventurer-created items such as food, and is rather curious about them, considering that the mind in control of the body is a Traveler, who normally are ephemeral. She takes a liking to being called "big sis" by Touya and Minori, and complains that her "big brother" (Shiroe) gave her an inconvenient subclass. However, despite taking a liking to Touya's Party, she finds human societies illogical and claims that they have an inefficient social structure.
Gold of the Kunie arc
After the Abyssal Shaft Raid Party wipes out, Roe2 appears near Seventh Fall, rising out of the snow and staring at the moon. On Mare Tranquillitatis, Shiroe notes that he had created an alt, meaning Roe2, on the test server.
Route 43 arc
Touya's Party, while traveling in the Sakawa Region, encounters a group of People of the Earth facing against a horde of Ogres when they first hear a voice through the trees warning them of more higher level ogres being on the way. As the Group is fighting the monsters, Roe2 appears out of the forest to join them in battle and summons a Princess Wraith to aid them in battle. She also formally introduces herself to the group and reveals that she is a vampire, as shown collapsing under the heat of the sun. In order to change her "cumbersome" subclass, she is also traveling to the south.
She mentions that she was on the moon, having switched with somebody approximately three months before the group met her and landing in Oou (the location of the Goblin King). After staying with the group in the town of Yuyugi, she volunteers to help them as long as they treat her like an older sister.
When hundreds of Wyverns invade, she watches with Touya and Minori as the Odysseia Knights charge at them, recklessly killing and being killed, even by their own men. They would revive soon after at their portable shrine and simply return to battle, prompting Roe2 to comment that they seem to be addicted to death. She continues on to say that she finds human social structures illogical and inefficient. At this, Minori, who has been curious about her existence, asks who she really is.
She explains who she is, but engages in much jargon that extends beyond both Minori's and the reader's understanding. Then, she participates in the battle, determining to assist her first friends in their attempt to save the town. After the battle, she departs after handing Minori a letter and requesting something from her.
The volume begins with Roe2's letter, addressed to Shiroe, which was written while Touya's Party was in Sapphir. The preface explains that she is a Traveler, a race of mental bodies that were brought to the world of Theldesia because of the Catastrophe, which they called the Eclipse (its kanji means "pact"). She continues to explain that her race is split into two factions: Fools and Genius, although she does not explain why at the moment, but states that this was the reason why she couldn't properly explain things to Minori. While the Travelers had an explanation for the Catastrophe, it wasn't a solid principle and they had no solutions as to how to return to their own world.
After splitting from Touya's Party, Roe2 heads for [Jack Sea for you Crunchyroll people], which is Elder Tale's equivalent of the JAXA Space Station. Around the time the Shibuya Raid Team defeated Tacritan, Roe2 single-handedly protected a rocket ship at Jaxea from the swarms of monsters, then wondering aloud if she had helped Shiroe and her "little siblings".
Although she isn't seen, when Shiroe first logs on after downloading the Homesteading the Noosphere expansion pack, her name, level, class, and location are seen in one panel. This is also her first official cameo in the entire series.
- Main article: Roe2/SNG
Roe2 has three different iterations in the mobile RPG: one Super Rare form, the Legendary Rare [Castling] form, and her Ultimate Rare form.
- Roe2's existence was first teased in Hara Kazuhiro's manga, where Shiroe's login screen showed that he had an alt. When asked about it during a 4chan Q&A session, Mamare Touno confirmed she would be a major character in the future, but also said "it's a secret!"
- Being Shiroe's former alt avatar, Roe2 speaks with a masculine tone (but still a feminine voice).
- Roe2's birthday, May 3, is the day of the Catastrophe. Whether this "birthday" is the day her character was created or whether it reflects the day that the Fool currently residing in her body took over is unknown. However, because Coppelia is also given a birthday (May 25), it's possible that Roe2 that it is the former.
- Her Sword Princess: Al Quinje seems to be an incarnation of one of the Ruquinjé, and Roe2 claims to have ties to them.
- Though Roe2 has not been officially confirmed as Log Horizon's Summoner, there have been many hints that she will be:
- In the mobile game's character archive, most characters are grouped by their affiliation/guild. Roe2, despite officially being listed as independent, is placed on the first page between Tetora and Marielle, while most other independent characters are placed towards the end of the archive.
- The teaser for volume 16 revealed at the Re:Fraction exhibit has Roe2 and Shiroe finally meet in what seems to be his office, with Roe2 telling Shiroe she wants to "compare answers" with him.