It's safe to bet that most teachers have experienced asking a simple question and getting no response from students. It is easy to let the student off the hook and let him go on to his seat, but it can be disconcerting to have such an easy question go unattended time and time again. The whole class can be asked to give possible reasons that someone could be late.
Students can be creative and exaggerate, or even stretch the truth.
Let's say that one reason given is that the student's mother didn't wake him up on time. Taking that idea, students can be asked to tell what they could say to their mothers when woken up. It can be a real question of curiosity and cross-culturally based when asked by a teacher whose first language is not Japanese. After the list is complete, students can be asked for any comments or corrections. Spelling could be corrected, or students could disagree as to whether a certain response is really appropriate or not, or whether to separately listed items are actually the same.