Honda Heihachirō was a vassal of Tokugawa Ieyasu and he’s remembered as one of the “Four Guardians” (Shitennō), the most skilled and faithful generals of the clan.
The warrior wears on the head the typical helmet kabuto with a decoration on the front (maedate) in the shape of deer horns. The weapons in the portrait are the two swords tachi and tantō and the spear with the side blade (katakama yari). 
He wears a sleeveless battle surcoat (jinbaori) over the armour, on which is embroidered the crest (mon) of the Honda clan, called “honda tachiaoi”, a variation of the Tokugawa mon that represents the direct bond with the shogunal lineage. This characteristic is extremely important because it help us recognize the portrayed warrior as Honda Heihachirō.