に気がつく => to notice; to realize N4
~こと請け合い => I guarantee ... N1
Happens next
いつしか => before one knows N2
Accept, agree
合う => do something together N3
からつくる/でつくる => made from; made with N4
~がほしい => I want ~ N5
Asking and Telling
~がほしいです => to want something N5
[合「あ」]う => To do A together/mutually N4
Secondary Verb
~みこみがたつ => have a good prospect N1
Expected
ひとつまちがえば => Just (negligence) N3
Ability
しかしながら => however, nevertheless N2
Things do not match the prediction
つきましては => about; concerning; regarding N2
Cause, reason