Ethics is one major subject of the philosophy in general like other subject as theology, aesthetics and logics.
Since Japan imported western way of learning at the Meiji restoration, unfortunately since then Japan put importance on scientific side which should be endorsed by the philosophy including theism which conflicts with the Japanese Emperor system.
Around that time Japanese diplomats made an investigation tour around Europe and found that western society is run under one God theory, so they decided to frame up the story the Emperor as God.
Objectives of the science is to pursue after almightiness and subjectives to pursue after universality.
Unfortunately Japan lack both attitude to pursue after either almightiness or universality.
And moreover, all the imported theory was for the society after Rene Descartes Dualism not for pre modern medieval Japanese society.
Japan made a remarkable progress in economy making full use of modern technology brought by the modern civilisation.
Even that was just a coincident people became like robots adopting pragmatism onto Japanese totalitarianism so these days American spells are faded away traditional Japanese endurance style organisation came back like Watami or Uniclo.
After the Meiji restoration, japan tried to expand economically making full use of the western way of learning with the Japanese spirit(Yamato Damashii), what we call Wakon Yosai(Japanese spirit and western way of learning), unfortunately it didn’t work out rightly.