Hiiro no Kakera - Season 1

It's the time of year when the trees turn red. Tamaki Ugaya, an ordinary high school student, goes to live with her grandmother in the Ugaya Family home while her parents are overseas for work. Tamaki arrives at Kifumura village, surrounded by nature. Her childhood memories guide her towards her grandmother's house but she is immediately attacked by monsters. The one who saves her is the surly boy, Takuma Onizaki

From her grandmother, Shizuki, Tamaki succeeds as the Tamayori princess to protect the Onikirimaru. Tamaki is puzzled, but surrounded by her guardians, Takuma Onizaki, Mahiro Atori, Yuichi Komura, Surugu Ohmi, who protect the Tamayori princess. Tamaki tries to find out what the Tamayori princess is and what the Onikirimaru is

The one who catches Tamaki as she nearly falls is the fifth member of the Shugogo house, Shinji Inukai. Despite their joyful reunion, Tamaki thinks it strange that Takuma and the others don't welcome him. Meanwhile, the five guardians head off patrol the five items which seal the Onikirimaru. Tamaki begins to worry and experiences a sudden headache..

Tamaki and the guardians discuss about the people they saw earlier which Yuichi comments that their names are the numbers from 1-4 in German, they find out that whenever Tamaki gets a headache it means that someone is trying to break through the seal barrier. The group decides to go to Ohmi-san to ask him about the artifacts and Fiona interrupts them asking why they are there and Takuma stares at her as he seemed suspicious of her and as she leaves she stares back at him. After school, as Tamaki and the four guardians on their way to Ohmi-san's house, Tamaki asks them about their interests. At Ohmi-san's house, he offered them tea and told them about the artifacts and that the artifacts originally belonged to the Tamayori princess. The group came to know that the artifacts are decorative things consist of: ring, mirror, necklace, bracelet and the bells and those five make the barrier and seal the onikirimaru which no one can break but the Tamayori princess and the guardians. Before the group leaves, it seemed that those people came to take one of the artifacts which caused Tamaki to feel pain in her heart and the guardians went to prevent them from breaking the seal. They encounter a little girl with blond hair which appeared to be Aria Rosenberg who claims to be the incarnation of Monado Cephelot accompanied by the people who named themselves the logos. The two groups fight together which ended with the logos defeating the guardians easily and Monado takes the bracelet which causes Tamaki to feel a great pain in her heart and the guardians lying on the ground and couldn't do anything to prevent them from taking the artifact. Takuma on a desperate attempt tries to retrieve the bracelet but it was all in vain. The episode ends with Baba-sama telling Tamaki that it's impossible for her to retrieve the artifact seal as long as she does not realize herself as the Tamayori princess.

Tamaki and the Guardian begins their second fight against Logos to protect the second seal.

After their loss to Logos and the second seal, Tamaki was in depression because she was no help to the Guardians. As Ashiya makes his move to help the Guardians, Aria and Vier starts to question Drei's loyalties to Logos.

Tamaki decides to have Ashiya's assistance, much to the Guardians' disapproval. When looking through the archives, Tamaki hears a voice that may be of help. Mahiro reveals a secret about Logos that he hid from everyone for her grandmother's sake.

While read the books in the storage, Tamaki finds a key information that may help her guardians. Meanwhile Drei finds a way to attack Tamaki while under house arrest, only to be stopped by Fiona who is revealed to be Vier.

After Aria punishing Ein, Zwei and Drei, she plans on imprisoning Drei for disobeying her. Meanwhile, the guardians all decided to live with Tamaki to protect her.

Aria and Vier find out their superiors are acting strange. Meanwhile, Tamaki and the others continue to research the history of the Tamayori princess and came across something important about Mahiro's bloodline and the truth of Takuma's lineage

Tamaki and the guardians prepare for the battle to protect to last two artifacts from Logos.

Tamaki and the guardians, desperate not to let Logos get the katana that holds Onikirimaru, stand up and fight with the rest of their strength and are prepared for the worst. Tamaki awakens as the Tamayori Princcess and saves Takuma from himself. This in turn helps Takuma to control the power of the katana. Devastated, Aria and the Logos leave.