Having successfully acquired a fully formed Gauna placenta (which just so happens to take the form of Hoshijiro), there's an opportunity for Sidonia's EBD scientists - or at least one of them, Numi Tahiro - to do a little experimentation with this incredible find.
Of course, it's Nagate that Tahiro turns to for help with this, as she's curious as to how this Gauna offspring will respond to him given that it seems to have been cloned from Hoshijiro. As it happens, this creature certainly responds to both Tanikaze's voice and appearance, albeit by seemingly trying to attack him, which quickly brings the experiment to an end. With talk of emigration rife across Sidonia and some nefarious business occurring in the basement of the traumatised Kunato's home, there's plenty of other concerns to be found across the ship too.
Regardless, Tanikaze's only real interest seems to be in "Hoshijiro", and after returning for a second, more successful experiment where he proves that this placenta recognises him by name, he spends more and more time stopping by to visit and watch it, much to the concern of his friends. Not that it seems to be affecting his performance as a pilot, however, as Kunato's "vacation" has left Nagate as a squad leader, a position which he takes on with aplomb as the ever-increasing number of sorties thrown the way of the ship's pilots all end in success. In fact, you'd be forgiven for thinking that things are going a little too well, and it might just be the apple of Nagate's eye that is about to play a part in the next bout of chaos that Sidonia will have to face.
Even though my eyes roll a little whenever Knights of Sidonia so much as brushes against its romantic harem possibilities, these brief moments don't detract from what is continuing to be a fascinating and very competent hole - the touches of politics interspersed into matters (this time around revolving around population numbers and emigration) add some very noticeable flavour to the world, and the progressing story regarding the Gauna as they relate to Tanikaze's relationship with The Placenta Formerly Known As Hoshijiro is both compelling and the provider of another tremendous cliff-hanger; something which the series continues to be good at, to keep me hooked week after week.