Big Boss Scree (ギギギの親分, Gigigi no Oyabun) is a yōkai who briefly appears in the series.
Big Boss Scree resembles a part of a tree with leaves that cover its whole body except its three eyes of yellow irises and purple roots which are a part of a parasitic shrub.
Big Boss Scree Exorcism
A small yōkai similarly looking like an ant enters Hanae and Haruitsuki's classroom. Hanae initially requests Haruitsuki to exorcise the yōkai but Haruitsuki declines. During lunch break that same day, Hanae witnesses the small yōkai clinging to a female student through the student's leg. Unable to ignore the situation, Hanae removes the yōkai from the girl. Fleeing from the scene, Hanae brings the yōkai with him when Hanae suddenly feels a terrifying chill from the yōkai who suddenly jumps off his hold and lets out a scream. As if in answer to the yōkai's scream, a horde of yōkai like the first one arrives. The horde clings to Hanae, who makes it back to his classroom, albeit lying down the floor of the hallway. Haruitsuki goes out of the classroom and sees the situation.
Haruitsuki correctly guesses that the little yōkai are just clones of a bigger and stronger yōkai. Outside the classroom, a larger horde of yōkai awaits Hanae and Haruitsuki. The horde catches a reluctant Hanae who was pushed, accidentally, by Haruitsuki, and immediately drags him away. Shocked by what happened, Haruitsuki follows only to be ambushed by another horde that was hiding above in the ceiling. The little yōkai successfully brings Hanae and Haruitsuki to a room where Big Boss Scree is in. Big Boss Scree is shocked to find two humans brought by the little ones. Big Boss Scree asks the two whether they can hear and see them (the yōkai). He comments that they are unusual humans and proceeds to ask, as they appear to be able to see and hear yōkai, whether they've heard of a particular yōkai, one that sends yōkai to the Underworld, and one who calls himself "Master of the Mononokean." Haruitsuki only asks if he has something to ask from the Master of the Mononokean but Big Boss Scree retorts that there's no point in telling it to humans. Haruitsuki responds by summoning a portal to the Underworld, surprising Big Boss Scree who states he wasn't expecting a human master. Big Boss Scree, despite being uneasy asking for help from a human, asks Haruitsuki to send them to the Underworld. Haruitsuki replies it is fine but starts to say another thing. Big Boss Scree interrupts him, saying he knows and Haruitsuki only needs to send the little ones first and he be the last.
Haruitsuki and Hanae sends off all the little ones, which leaves the Big Boss Scree as the remaining one to be sent off. Hanae states this but Big Boss Scree only asks if he didn't understand. A baffled Hanae hears Haruitsuki shutting the portal close, and asks why as the Big Boss is still there. Big Boss Scree asks Hanae to look closely at his body. He states that he's already spread his roots in the mundane world and as such, can't leave anymore. Haruitsuki states that the roots are called parasite shrub and that it attaches to yōkai to restrain their movement and drains them of their energy to grow. Big Boss Scree adds he's long thought of sending the little ones to the Underworld before withering to die and thanks the two for granting his request. Hanae asks whether the little ones knew about the situation, to which Big Boss Scree answers they did not as he didn't want to worry them. Hanae calls him a coward for wanting to disappear without a word to the little ones. Big Boss Scree explains himself, that he has thought many times that he must say good bye only to think he wants to scream he doesn't want to leave them. He adds that he'd be willing to tear his body in half if it means he could go with them as watching them grow gave him a reason to live. But he concedes that they would be safer in the Underworld as he can't protect them anymore. He states the he has only one wish, that is to watch over the little ones until they grow enough to take care of themselves but that is a hope he must abandon now.
Haruitsuki asks Big Boss Scree whether he really is determined to go to the Underworld in any possible way and states that there is a way, a medicine that will weaken the parasite shrub. However, the medicine will also cause the yōkai tremendous pain, some have even died of it. Big Boss Scree thinks of the new possibility he can be with the little ones until his body withers. He concludes that he doesn't want to be apart from them. Big Boss Scree finally decides to ask Haruitsuki to send him to the Underworld and takes the risk of the medicine. After taking in the medicine, the parasite shrubs burn away, causing Big Boss Scree to faint in pain. Big Boss Scree shrinks in size, which Haruitsuki claims is due to the medicine and also due to decrease of the anxiety the yōkai feels.
Big Boss Scree wakes up and is immediately embraced by Hanae, joyful of it. Big Boss Scree screams it hurts. Haruitsuki thinks to himself that it is amazing how the yōkai is still strong enough to scream. Big Boss Scree prepares to leave through the portal. The three find the little ones still at the door, awaiting Big Boss Scree. This moves Big Boss Scree, who states he's glad he didn't give up. Big Boss Scree thanks Haruitsuki and Hanae again for helping him. Hanae apologizes for his earlier behavior, as if he understood how the yōkai felt. Big Boss Scree only thanks him for helping him avoid being a coward. Big Boss Scree and the little ones depart for the Underworld and bid good bye to Haruitsuki and Hanae.
Big Boss Scree can make a clone of himself. All the little screes are his clones.