Hikari

From town to town, riding his beloved horse Storm, Hikari is a dashing hero who vanquishes evil with his twin pistols. Pen-kun, a street urchin, plots revenge against the man who imprisoned his father. But as he stalks him on his travels, the two eventually form a strong bond, becoming a legendary duo. A thrilling, timeless action adventure!

(Source: Tezukaosamu.net, translated)

Note: Serialized in Manga Ou from 1959-06 to 1959-12