Kurenai Sanshirou

Both are original Tatsunoko property and old episodic TV series about a teenager fighting in the purpose of taking vengance for their families. Both Casshern and Sanshiro also voiced by the same voice actor  

Both are episodic martial arts series that were made by the same creators  

These are basically cheesy old school kung-fu movies. If you enjoy those you should be right at home here. 

Both are late 60’s shounen anime about sports and with plenty of action, drama, and violence, and are very similar for character design, animation, and general mood.