Final answer:
The statement 'Life is Sweet at Kumansenu' most prominently uses a metaphor as it directly equates life with sweetness without employing 'like' or 'as'.
Step-by-step explanation:
The rhetorical device used most prominently in the statement 'Life is Sweet at Kumansenu' would be a metaphor. A metaphor is a figure of speech that compares two things by stating that one is the other. In contrast, a simile would use words like 'like' or 'as' to draw comparisons. The phrase 'Life is Sweet at Kumansenu' does not use 'like' or 'as' but rather presents life as being directly synonymous with sweetness, which is characteristic of a metaphor. This differs from a hyperbole, which would exaggerate something greatly, or personification, which would attribute human characteristics to non-human entities.