Is it O.K for a Buddhism(Mahayana) to believe and worship in Shinto Buddhism's Deitie

Im the Buddhism(Mahayana) in this case.....
Just wanted to know as all the deities are similar in both the religion only with different name....
Correct me if I'm wrong....

it is OK only, but only if done while wearing their underpants on the outside

Yes, Buddhists are allowed to believe in both Shinto and Hindu deities and most real Buddhists do.

We don't worship other deities like the Christians or Shinto followers do, given their ?Deity? the heart and souls (a fallacies- but I must use the same word and terminology they use).

As a Buddhist you must "Truly" understand the reason for that, unless you are one of those book-Buddhists, someone who read few Buddhist books and arbitrary decided you are now a Buddhist, without ever go to a temple or recognized center to do your confirmation and receive teachings. Even a Christians must go to Church to be baptized, so does a Buddhist must go before the Buddha, Dharma and Sangha to affirm their ?Refuge?.

As a Buddhist, we whole heartily take ?Refuge under three Jewels- the Buddha, the Dharma and the Sangha?, but we only pay respect to other deities that are non-Buddha, Bodhisattva levels deities.

Always remember when you take "Refuge" to "Three Jewels", you no longer worship other deities or take refuge to them. Realizing those deities are the outer paths, those are the sentient beings, they may be Heavenly Beings, but no different from you. They can't control their own destinies, when their time to die, they will flow where their karma will lead them.

Sometimes, we have "Feasts" ceremonies in honor of various deities in Vajrayana Buddhism and even Sutrayana Buddhism, but you must realize the purpose is like treat your good friends to a nice dinner. You don't worship them; you pay respect to them or treating them to feasts, as a good friends or as thank you postures for their protection, cooperation or as your servants to do your bidding.

*** In case you don?t understand what refuge means, it means you rely on Buddha, his teaching (Dharma), and his representatives- the Sangha (Monks, Nuns and your Buddhist teacher for teaching, your Dharma friends and your Dharma brothers and sisters for support.)

Yes it is OK.

In text books, people refer to Buddha, Dhamma and Sangha but in reality, they believe that Buddha does not merely represent Goutama but also does Amitabha, Vairocana and others as well as Bodhisattva deities. Many Japanese worship Buddhist and Shinto deities as do all real Asian Buddhists. White Buddhists are not real Buddhists and so in practice Asian Buddhists have no issue worshiping any deities they please. And yes, the deities are worshiped for protection and help and influence -- not as friends or servants like some white Buddhists pretend. Buddhist deities have all the powers of other deities and more and most of them are also based on Hindu deities.

It's fine to worship both Buddhist and Shinto aspects.

Shinto focuses on harmony with nature and society through the Kami in this life.

Buddhism considers this life nothing more than a preparation for the next.

Buddhism and Shinto are complementary. Typically you go to a shrine (Shinto) for life-affirming events: New Year, Marriage, success in business/school/love, etc. and a temple (Buddhist) for funerals and ancestor worship. Until the Meiji Restoration of 1867, when the state tried to separate the two, Shinto didn't even have funeral rites because dead bodies are a source of contamination which Shintoists avoid.

Neither religion is into "gotta go to church on Sunday so the neighbors will see and so money can be given to the priests". Most Shintoists and Buddhists have a home Kamidana (Shinto) or Butsudan (Buddhist) where they do the majority of their praying. Many homes have both.

Shintoists consider all religions Gods just another Kami, so there is absolutely no restriction in also belonging to another religion.