合う => do something together N3
[後「あと」]で => After V1, V2 N5
Time
~こと請け合い => I guarantee ... N1
Happens next
[合「あ」]う => To do A together/mutually N4
Secondary Verb
〜がさいご(が最後) => if you do... negative result N1
Decisive (resolute decision)
場合(は) => in the event of; in the case that ~ N4
~ににあわず (に似合わず ) => ~Different from N1
Evaluate
たが[最後「さいご」] => Once A occurs, B happens N1
Information, Report