Zebrakenko (all one word) was a Japanese bicycle company formed in 1901. They started importing to the US around 1974. That is definitely the mid-1970's headbadge ( one of the nicest) and from what I can see of the decals, they match the era too. At the time, they had a range of about 9 nine models. Yours is one of the entry level models, maybe a Thunder. A drive side pic where the derailleurs and crankset are clearly visible would aid in identifying the model.
It's a nice, clean expample of a Japanese, boom era, entry level model and a very good purchase for $10.