for the comments asking why pick guts buff during junior phase instead of stamina due to the deck used for it speaking from experience alone, it's mostly to prevent stamina being maxed out earlier especially during classic phase, stamina gives a bit of guts stats during training so getting the guts buff on junior phase should increase it a little
0:11 デビュー前
2:42 ジュニア期
6:03 クラシック期
9:20 夏合宿
13:54 シニア期
19:00 夏合宿
22:57 URAファイナル
25:26 育成完了時