Did the Japanese not think of shields?

With how effective archers are in this.. didn't they ever think of using shields or something? =p

And before someone tells me using a shield is shamefur dispray.. shouldn't using bows be just as shamefur?

They did use shields in sieges - but large pavises to hide behind.

And almost all of their military weapons were two-handed: katanas (which can be used one handed but less effectively), naginatas, long spears, bows, staffs, huge tetsubo clubs....

In any case in the earlier Heian and Kamakura period the samurai were primarily horse archers anyway and used a box-like form of armour with large shoulder pieces which did to some degree provide shielding but made it impossible to use any hand-hand-to-hand weapons other than a dagger - which is why most of the combats in the Heike Monogatari take the form of horse archery duels ending with grappling and a dagger stab.

While later Ashikaga and Tokugawa period armour is much more practical they switched primarily to long spears and katanas - and then eventually to firearms.

The Chinese and Koreans from whom they acquired much of their military technology didn't make much use of shields either - being similarly devoted to the use of two-handed polearms, bows and crossbows.

They also used shield in the classical period. In fact their levy system was copied from the Chinese Sui and Tang dynasties armies, with similar armaments including rectangular hand shields. However as time went by, the regular army was phased out in favour of privately raised provincial warbands (IE Samurai), mainly to deal with the Emishi in Mutsu and Dewa.

The kind of operations carried by this warbands favoured Horse Archer tactics wich meant shields fell out of use aside from pavises and mantlets used in sieges and ships.