The concept of self-defense takes such an important place in the UN Charter and international law. The concept of collective self-defense should also be interpreted and applied within the clear parameters of stated principles of the UN Charter. This is not a concept that can be elastically applied so as to cover a wide range of instances that require military action by like-minded States acting in response to contingent situations. The discussion of collective self-defense within the specific context of Japan at the moment, however, seems to involve issues larger than or beyond the traditional concept of self-defense. Arguably, some aspects of the issues posed seem to fall under the collective security realm which is reserved to the authority of the UN Security Council or which at least requires authorization or delegation from the Security Council. Using the term collective self-defense to address a wide spectrum of military contingencies to be tackled by collective security regime may not square with the provisions of the UN Charter.

Islamic international law is a branch of the Shari’ah (Islamic law). Due to the classical doctrine of the notion of‘ Jihad,’there have been misconceptions and Islam has been painted as a religion encouraging violence and war. This paper appeals for the reconsideration of the classical doctrine, which was adopted at a time when there was a state of war between Islamic and non-Islamic states. Going back to the roots and referring to the Qur’an and the Sunnah: the two primary sources of Islamic law, the paper argues that Islam prohibits aggressive war and that the essence of‘ jihad’ is‘ self-defense.’After elaborating the essential conditions of the right of self-defense, the paper concludes that Islamic international law can contribute much to the present world order by providing moral and ethical values that modern international law is lacking.

Excessive self-defense is applicable if an act of self-defense exceeds the reasonable limits and lacks requisite appropriateness. Excessive self-defense is not punishable under Article 21, Clause 3 of Criminal Law, if it is caused by fear, astonishment, excitement or confusion under anxious circumstances such as during night time. According to Article 21, Clause 2, in case of excessive self-defense under extenuating circumstances, either a reduced sentence or is unpunishable. The illegality and liability of excessive self-defense under Article 21, Clause 3 are reduced and besides its liability is expirated because it can not be expected that an offender acts within legal boundaries under such circumstances. Under Article 21, Clause 2, the illegality and liability are reduced and it is unpunishable because it lacks the necessity for punishment. Excessive self-defense is a complicated matter connected with criminal liability, illegality and sentencing. It is not easy to grasp the nature of excessive self-defense and its applicable range because it borders on self-defense and mistaken self-defense, and is indistinguishable from them. The Supreme Court has not clarified its stand on the requisites of excessive self-defense. The Supreme Court has interpreted not only the requisite appropriateness of self-defense, but also the requisites of excessive self-defense strictly. It ruled a decision upon the above mentioned first case as excessive self-defense and the second case as self-defense. However, it should have ruled that self-defense was justified regarding the first case and ruled the second case as mistaken excessive self-defense with either reduced liability or an expirated sentence.

The induction of enzymes and the accumulation of their end products associated with self-defense mechanism in rice were investigated. When rice leaves were irradiated with UV light, activities of diterpene cyclase, phenylalanine ammonia-lyase (PAL), and cinnamic acid 4-hydroxylase (CA4H) were induced and rice phytoalexin, momilactone A was accumulated. The content of p-coumaric acid in rice leaves was closely correlated with self-defense or allelopathic potential against barnyardgrass. UV-challenged rice leaves gave rise to the inhibition of barnyardgrass growth