Visitor Arc V is the fifth episode of the second season of the Mahouka Koukou no Rettousei anime.
A parasite is an information body that was generated from the spirit dimension. How could an entity from another dimension appear in the physical world? An evil visitor of unknown origin infiltrates its way into First High School.
January twenty-second. Mayumi is guiding Mikihiko from the Chiba search party as well as Master Clans teams to hunt the parasites by tracking the radio signal. The two groups decided to work together after Tatsuya’s meeting. Mayumi feels like Tatsuya is using them and plots revenge on Valentine’s Day.
At home, Tatsuya and Miyuki receive a call from an inebriated Shizuku. Shizuku tells Tatsuya about the experiment which created the parasites. Tatsuya explains the scientific theories and theorises that the parasites are from another dimension and entered this world due to the black hole experiment breaching the dimensional boundary.
January twenty-third. Erika is telling Mizuki about the parasite hunt from the night before and how it escaped but to having unexpected backup. Mizuki asks if Erika is fighting with Tatsuya, flustering Erika. Erika tells Mizuki they aren’t fighting, it’s just awkward as she relies on him too much and assumed that he’d come with them without her asking and got upset when he was helping Mayumi. Mikihiko arrives with sandwiches from Tatsuya since Erika is avoiding him.
A van arrives at First High and as it enters the barrier around the school, Mizuki, Miyuki and Lina all instantly react. Mikihiko puts up a barrier to protect Mizuki, who is in pain, and Mizuki tells them she can sense an ‘evil presence’. Realising it’s a parasite Mikihiko and Erika spring into action and unusually, Mizuki insists on coming too.
Meanwhile, Lina rushes towards the parasite, realising it’s where Mia should be.
Elsewhere, Silvie makes a discovery in her investigation.
Back at First High, Miyuki senses the parasite and tells Tatsuya, commenting it must be a pushion wave if Tatsuya cannot sense it. Tatsuya gets a call from Mayumi and she tells him the parasite is near the lab building’s service entrance, likely among the Maximillian staff delivering equipment. Tatsuya and Miyuki activate their flight devices, leaving Honoka alone on the roof.
Tatsuya and Miyuki conceal themselves and spot Lina arriving and greet Mia. Using Elemental Sight, Tatsuya sees Mikihiko’s spirits surrounding Mia, who swats them absentmindedly, which confirms to Mikihiko she is the parasite. Mikihiko explains this to Erika, Mizuki and Katsuto, the four hiding separately from the Shiba siblings. Erika assumes Lina must be an accomplice and has to be stopped by Mikihiko so he can erect a barrier for Sense Tuning to block sound and sight but states it won’t work on the machines. Juumonji states he’ll deal with the cameras and sensors. Seeing the barrier go up the Shiba siblings prepare to act.
Inside the barrier, Lina and Mia are confused as to what is happening when Erika charges in with out warning. Lina pushes Mia out of the way at the last moment and tries to stop Erika from attacking Mia but is blocked by Katsuto. Erika lands a solid strike on Mia, but she blocks it with her bare hand, shocking Lina. At that moment Lina gets a call from Silvie revealing to Lina that Mia is the parasite they were hunting. Lina is shocked as Mia turns, her eyes now that of a parasite. Erika attacks again and stabs Mia through the heart but Mia just continues attacking whilst regenerating the wound. Before the fight can continue, Miyuki ruthlessly flash freezes Mia.
Mia frozen, Tatsuya enters the barrier and tells Lina that Mia is coming with them. Lina reluctantly agrees. Erika however demands custody. Tatsuya simply states he doesn’t care who takes her so long as the results are shared.
The frozen Mia launches a surprise attack with magic, which is blocked by Katsuto and dispelled by Tatsuya. Mia then self-destructs and the group come under attack from lightning, forcing everyone on the defensive. Miyuki shields the otherwise defenceless Erika whilst Mikihiko shields Mizuki and the other four defend themselves back to back. Tatsuya uses Elemental Sight but cannot perceive the parasite well enough to attack. They wonder why it doesn’t flee and theorise it wants a new host. Mikihiko realises it’s targeting Erika who has no means of resisting it but cannot attack as he cannot see it. Hearing this Mizuki asks Mikihiko to lower the barrier protecting her so she can use her eyes to find it. Mizuki quickly finds the parasite and gives the location to Mikihiko, who hits it with Karura-En. Tatsuya then uses this to get a lock on its location using his Elemental Sight. The parasite realises and tried to attack Mizuki but Mikihiko defends her with Exorcism Cut then Tatsuya blasts it with Gram Demolition, forcing it to retreat. The fight ending in a draw leaves a bitter aftertaste.
The fleeing parasite finds its way to the Robot Club room and infests Pixie.