It's the same world as the first Our Life! This is the timeline-
Our Life 1:
Step 1: 2006, the MC is 8
Step 2: 2011, the MC is 13
Step 3: 2016, the MC is 18
Step 4: 2021, the MC is 23
Our Life 2:
Step 1: 2010, the MC is 10
Step 2: 2014, the MC is 14
Step 3: 2018, the MC is 18
Step 4: 2022, the MC is 22