Hm, is that a glaive or a naginata Tatsuta's using? (On that note, how do we even tell which is which?)

Naginata, I would say. The Glaive is a sword. The Naginata looks more like a spear with a blade at the end...

Type-kun said:
Hm, is that a glaive or a naginata Tatsuta's using?

According to Kancolle wiki, it's a glaive.

etb said:

The Glaive is a sword.

Glaive on Wikipedia. Glaives are medieval polearms.

To answer Type-kun's question, though, the distinction between the two mainly comes down to whether it was Japanese-built or not. Similar to a "Yari" and a "Western" spear, there wasn't a strict, formal way that all naginata or glaive had to be made, so you could find overlap in the way they were constructed to the point where the difference is mostly just in who built it. Basically, what a Westerner would call a glaive, a Japanese person might look at and call a naginata.

However, Japanese construction tended towards having a much thinner, and much more notably curved blade that tended to look more like a bending knife blade no thicker than the pole it was attached to. They also had a tang, like a sword, which is a portion of the metal blade section of the weapon that actually goes into the haft or hilt portion of the weapon, while glaives are socketed like an axe (showing the differences in their evolutions). (Not to confuse the matter too much, but if Tatsuta's weapon's head were bolted on from the side, it would have been a voulge.) Glaives, designed to cut through thicker armor or be held against a much heavier charger than the light Japanese cavalry, were much thicker weapons with a more cleaver-like blade jutting out from the pole.

More modern Japanese construction of naginata is usually based around form over function, like the way that katanas were redesigned to be much longer than they were in actual practice after the end of the Sengoku Jidai. They tend to be even thinner and less practical for combat against an armored opponent (and most are purely wooden practice weapons).

As a side-note from NW-san's explanation, the constructions of weapon being thin and long in Japan comes from the fact that the lands lacks the resources to make bulky weapons, namely iron ore (and even the present ones are full of impurities)-this leads to the motion to recycle metal materials as efficient as they can get, be it broken weapons or looted metal items from enemies. As for that fact, naginata heads MIGHT or MIGHT NOT comes from re-tempered broken katana blades.

NWSiaCB said:

More modern Japanese construction of naginata is usually based around form over function, like the way that katanas were redesigned to be much longer than they were in actual practice after the end of the Sengoku Jidai. They tend to be even thinner and less practical for combat against an armored opponent (and most are purely wooden practice weapons).

Explains why modern katanas has the length of a nodachi