In book four, unfulfilled by the teachings of renowned ascetics, Siddhartha agrees to follow Dhepa into the forest of trials. But the final ordeal of little Assjai proves to be his most poignant lesson. As Siddhartha searches his heart and yearns for his family, the Kosalans discover the true caste of their queen – a despised shudra, disguised as a noble kshatriya. For the insult, the Buddha’s homeland will pay dearly. Originated in the 1970s, Buddha is Osamu Tezuka's unparalleled rendition of the life and times of Prince Siddhartha. Tezuka's storytelling genius and consummate skill at visual expression blossom fully as he contextualizes the Buddha's ideas; with an emphasis on, action, emotion, humour and conflict as Prince Siddhartha runs away from home, travels across India and questions Hindu practices such as ascetic self-mutilation and caste oppression.

Rather than recommend resignation and impassivity, Tezuka's Buddha predicates enlightenment upon recognizing the interconnectedness of life, having compassion for the suffering, and ordering one's life sensibly, his approach is slightly irreverent in that it incorporates something that Western commentators often eschew, namely, humour.