I am currently creating a mystic adept with the mentor spirit wise warrior, that is supposed to follow the code of the bushi (would have taken that code of conduct, but I had filled the Karmapoints for positive Qualities already).

Unfortunately I am very unsure about the magic tradition I should chose. Shamanism doesn't fit well, neither does the hermetic tradition. Also Shinto and Buddhism don't seem to do the job. For any suggestions how to create a bushi I would be very grateful.

Hermetic could work out just fine, but so too could almost any of the 'religious' traditions - a code of honor and a magical tradition don't have to be interlinked. Use the interactions of the two to create a deeper character.

Create your own.

Run it past the GM.

Just to make sure. In SR4 the mentor spirit and the hermetic tradition are compatible?

Yup

You mean that Shinto and Zen Buddhism don't fit a martial philosophy developed and adhered to by a warrior caste that was almost exclusively some combination of Shinto and Zen Buddhist? I'm shocked.

The Buddhism described in the Street Magic is unfortunately not Zen Buddhism, but especially Vajrayana Bhuddism (and maybe also Hinayana & Mahayana). The Shinto Tradition is definetely more interesting for me, I wouldn't exclude it, just the notion of that the followers of Shintoism do not follow
the ideals of a particular totem, but instead try to reach a state of harmony with the collective body of the "eight million kami" spirits seems problematic towards the single Mentor spirit, which I clearly picture as an ancestor.

And in general you also wouldn't use a jewish or christian tradition, if you want to play an islamic mage, just because Islam has mainly developed out of jedaism and christianity, right

Personally I'd go with Shinto. There's nothing to stop you having a mentor spirit using it and in the back of Street Magic it even lists the more common mentor spirit choices for the Shinto (along with a bunch of the other new traditions).

There's always the re-fluffing option: Go with the tradition whose mechanics fit, then give it a different name and philosophy.

that one seek balance to not preclude having a mentor or teacher showing the path forward...

It's hard to say. Many samurai who followed Bushido where buddist, and I think that tradition would make the most sense(a little change in fluff is all thats neccesary). Heck, you could even make a Bushido tradition(intuition based, most likely possession, guardian, task, man, beast, guidance if I had to do it off the top of my head).

Shinto, Vajrayana Buddhism, or Wuxing would all work as possible traditions. Bushido, on its own, isn't really a magical tradition, it's a warrior's code of conduct. It doesn't really have a whole lot to say about magic or spirits.

Yup. The only "traditional" role for a SR style mystic adept is with the Ninja.

The ideal rarely filters down to reality when a kami can offer you knowledge and power, and so there are going to be people who adhere strongly to a mentor spirit despite the warnings of their religion against doing such a thing.

Most samurai were actually Ryobu-Shinto, or a blend of Buddhism and Shinto. You can mix and match the elements of each to produce a tradition more to your liking.

As far as having a mentor spirit goes, it's not uncommon for Shinto followers to have "patron kami", a particular kami that they've dedicated themselves to. Most Shinto shrines in Japan today work on this principle: the shrinekeepers venerate all kami, but devote themselves to the kami of a particular place.

Anime Poserism

This magical tradition is a hodgepodge of Shinto, Zen Buddhism, and Christian theurgy (Catholic priests, called nuns, worship the Saints) gleaned from various animated Japanese trideo shows.

Drain Stat: Charisma
Spirit Type: Materialization

Earth - Illusion
Fire - Combat
Wind - Detection
Water - Manipulation
Heart Beast - Health

Spell flavor suggestions:

Increase Strength = Strength of One Thousand Beast King God
Trid Phantasm = Ten Thousand Mind Bending Illlusion Power
Analyze Panty Color = What that guy from City Hunter can do.
Power Bolt = KA-MA-HA-ME-HA!!!!

Mentor Spirit Flavor Suggestions
Wise Warrior = Hachiman, the Japanese God of War who once assisted a famous samurai and Leon from The Professional in their battle against Oda Nobunaga and his army of demonic Shakespeare characters.
Horned Man = Shikima King, he has tentacles.
Sky Father = Judeo Christian God, who vacillates between benevolence and maliciousness depending on the series.
Trickster = The red-haired plant/Fox guy from Yu Yu Hakusho.

Spirit Flavor Suggestions:
I choose you!!!

Preferred Geasa: Gesture and Incantation (Name of spell) are strongly recommended.

Inititory groups:
Anime Poser groups generally consist of 5 members, four male and one female. The members are color coded based on function and preferred element, with the female member usually being pink or white and often preferring water. A large muscular member is not uncommon, and is usually yellow. On occasion, a sixth member may be added, temporarily, if his skills are useful.

Preferred Ally Spirits: Anime Posers prefer Inhabitation ally spirits hybrid merged with walker-modified vehicles, often modified to combine with other similarly modified vehicles to form one giant vehicle.

^^ ^^

The kind of Buddhism practiced by the Yamabushi sounds like it would fit your need. Their mystical powers are mainly derived from Shingon Buddhism which is heavily influenced by the Vajrayana school. Esoteric Buddhism was far more common among the samurai than most people realise, some of the older Ryu-ha explicity teach their students magical practices to help them in combat and the hand movements used by ninja as focus aids are derived from the same source.

The samurai as zen warriors came relatively late, developing around the same time as the romantic idea of bushido that began to develop during the 17th Century and eventually resulted in the madness of Japanese behaviour during WWII.

Maho no Go Rin No Sho

Magic of the Book of Five Rings


Drain Stat: Intuition
Spirit Type: Materialization

Earth - Manipulation
Water - Detection
Fire - Health
Wind - Illusion
Guidance - Combat

Miyamoto Musashi's Book of Five Rings lays the template for the Two-Sword Way. It is considered one of the classics of Samurai training.

The first ring, Earth, describes the basic concepts of Martial Arts, leadership, and control over your environment (Manipulation). The second ring, Water, describes how to maintain awareness of your surroundings, and utilize every tool in your arsenal to succeed. The third ring, Fire, describes the flow and timing of combat, and how to synchronize the rhythm of your body with the rhythm of the battle. The fourth ring, Wind, describes other martial techniques and their failings, and how those failings and assumptions can be exploited. Finally, the last ring, Void, provides the fundamental insight and philosophy necessary to a Warrior.

I am also tempted to use the book of the five rings as a basis and in principle agree with you on the choice of Spirits, but I guess I would arrange them differntly. But I find it difficult to do so

here is one order I set up, but I'm not happy with it.

Book of:
Earth = Healing (the strength of the warrior comes from his center)
Water = Combat (be flexible as water)
Fire = Illusion (blind your opponent, so he can't foretell your next move)
Wind = Detection (this one is more a gut feeling)
Void (Guidance) = Manipulation

For some help to sort out the ordering I'd be grateful.