I Traveled Through Tokyo for Twelve Years Before Realizing My Childhood Friend Was Shiki

[Day 1 of time travel, Tokyo, Japan. I'm just five years old. Good news: my family is rich. My childhood friend in a kimono is adorable.] [Day 3, bad news: 1983, Japan's bubble economy is on the verge of collapse. Coincidentally, my family is in real estate...] [Day 10, Holy crap! A system! My childhood is saved! This skill makes money, learn it! This skill increases intelligence, learn it! This skill can see through lies, learn it! And combat skills? Too expensive, using them would only increase medical expenses and compensation costs, don't learn it.] [Year 6, the real estate economy collapses, many companies go bankrupt, but my family's business is booming. We invest in schools, build bridges, and even take over the bankrupt main family's assets. Our time to separate and hold our heads high has come!] [Year 6 and three months, the main family's woman remarries my father. My new, cheap cousin is adorable.] [Fifteenth year, university opening ceremony. I meet my childhood friend whom I haven't seen in a long time. She says her name is Ryougi Shiki.] Is it too late to learn magic now? Nobody told me this was Type-Moon!