It appears like any regular Zanpakutō. Though it does hide a small vial of healing ointment in the base of the hilt. Hōzukimaru's cross guard is an oval, with what look like three small teardrops in relief on both the top and bottom end.
Shikai: Its Shikai command is "Grow" (延びろ, nobiro). Hōzukimaru's Shikai is unusual in that wielder has to slams Hōzukimaru's hilt (and sometimes its pommel) into its sheath to activate it when saying the command phrase. Once activated, Hōzukimaru takes on the form of what initially appears to be a naginata (spear) with a wax wood shaft. The pommel also has a red horsehair tassel. While able to deliver powerful blows, it is not very durable as it tends to break against particularly strong strikes.
Shikai Special Ability: it uses the command "Split" (裂けろ, sakero) to separate the naginata into its true form which is a Sansetsukon (Three Sectional Staff), after which the sections can independently reconnect and separate again at will. This special ability surprises one's opponents when they first attack. These chains are also able to extend a fair length, allowing wielder to swing the weapon like a flail for mid-range attacks.
Bankai: Ryūmon Hōzukimaru (龍紋鬼灯丸, Dragon Crest Demon Light): It keeps the three-section theme but loses its naginata properties. Instead, it is merely three over-sized weapons connected by an equally large chain. It's two main weapons are a Chinese Monk's spade and a standard Guan dao. Both have a traditional horsehair tassel at the hilt and a long cylindrical weight for a pommel. The pommels are connected by a heavy chain to the center section, which resembles an axe-like blade with a parallel handle forged into the blunt end and a dragon crest on one side of the blade. It takes an incredible amount of strength to wield such a weapon.
Bankai Special Ability: the Bankai, like the Shikai, is quite unusual. Aside from the increase in power, the Bankai offers no special abilities and no special defense properties. It releases some ki which starts to grow in strength. Hōzukimaru is a lot different than zanpakuto because if wielder forces it to awaken suddenly, cutting the enemy and not getting cut
becomes a lot harder to handle than it should be. Thus the Bankai gets increasingly more powerful as the fight drags on. After Bankai is performed, the dragon crest will slowly fill in with crimson dye as wielder's Spiritual energy rises. It fills faster when they spin Hōzukimaru with the center handle. Hōzukimaru is actually very lazy in battle and needs to be woken up through causing or receiving injury; which would explain its ability to accumulate attacking power the longer the fight extends. When the crest is completely filled, Hōzukimaru is at its full power. However, the force of unleashing so much power can leave the Zanpakutō's edge brittle under excessive stress.