Underworld (アンダーワールド Andāwārudo) is the 16th chapter of the Prison School manga, serialised in Weekly Young Magazine on June 13th, 2011 and published in tankobon format in Volume 2 on October 6th, 2011.


On Tuesday morning, Meiko is undergoing intense excercising (Hindu squats) during her guard duty when Kiyoshi asks her for toilet leave. After she grants him his leave, he goes to the sports ground toilets where he continually worries about the distance from the toilets to the escape hole. When Kiyoshi enters, he discovers a window inside his cubicle leading to the waste disposal area where Gakuto is working. Kiyoshi climbs thorugh then appears in the sewage drainhole below Gakuto in the waste disposal area, suprising Gakuto. He then reveals that there is an extensive underground sewage pipe leading from the toilets to the sports field. When he returns, he overhears Shingo telling Andre and Jo that Gakuto and him are in a 'physical relationship' (from his misinterpretaion of the two in the baths the day before). Though it unsettles Andre and Jo, Shingo says that he still thinks of the two as his friends.

Their conversation annoys an eavesdropping Kiyoshi as the convienience of being alone in the luggage team came at the price of him being percieved as gay (which he can't correct without revealing the breakout plan). He sees Meiko sending the three boys back to work and then ends up crawling below an eyehole directly below her (allowing him to watch her panties while she completes more squats from below). As he moves to crawl away back to his working area, Meiko's heel enters the gutter and stabs him in between the buttocks, to his utmost pain. When the boys are rounded up by Meiko for the end of the work shift, Meiko asks Kiyoshi why he spent a long time in the toilets. When Gakuto makes a poor excuse about him having a weak stomach, Shingo interrupts to say that Kiyoshi has haemorrhoids (as he started bleeding when Meiko's stilleto stabbed him). The boys then more deeply suspect the two of being gay as a result, sparking miscomfort in Gakuto.



  • The chapter title is a cultural reference to American horror thriller film Underworld.


Prison School by Akira Hiramoto
Volume 1:
Volume 2:
Volume 3:
Volume 4:
Volume 5:
Volume 6:
Volume 7:
Volume 8:
Volume 9:
Volume 10:
Volume 11:
Volume 12:
Volume 13:
Volume 14:
Volume 15:
Volume 16:
Volume 17:
Volume 18:
Volume 19:
Volume 20:
Volume 21:
Volume 22:
Volume 23:
Not in Volumes:
Non-Canon Chapters
Fukukaichou Gambaru:
Anime Promotion:
Other Series:
Other Series:
  • Fukukaichou Gambaru
  • Agonashi Gen to Ore Monogatari
  • Me and The Devil Blues
  • Yarisugi Companion to Atashi Monogatari
  • Sono Tomodachi no Gimon Ari
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